DialCodesPlus

+377 Monaco

Dial +377, then the national number.

ISO
MC
Region
Europe
Exit code when calling from Monaco
00
Difference
Not calculated
--:--
In Monaco
--:--
Monaco UTC—
Your time is read from this device's clock; nothing is sent.

Your zone is guessed from the device. Pick another if the guess is wrong.

Monaco at a glance

microstate in Western Europe

Capital
Monaco
Official languages
French
Currency
€euro
Population
38,8572025
Overview map: Monaco highlighted; Monaco marked. Country overview from Natural Earth; capital positions from Wikidata may differ from the outline. The marked source position lies outside the retained land polygon. Source precision is not an accuracy radius.All 1 geometry parts and 1 rings retained. Exact selected Natural Earth country/map-unit extent; preserve source hierarchy and classification. No current legal-boundary or telephone-coverage assertion. Country overview from Natural Earth; capital positions from Wikidata may differ from the outline. The marked source position lies outside the retained land polygon. Source precision is not an accuracy radius. Country rings omitted: 0. Context rings omitted: 4. Monaco: the source position falls outside the retained outline; the location is approximate at this scale.Monaco
Small islands and neighbouring detail are not drawn.

Dial it

Calling Monaco

Dial this
Type a number

Try

Calling from Monaco

Monaco's listed exit code is 00. Your provider may differ; check its instructions.

How to call Monaco

  1. Dial your exit code

    Use the international access method for where your call starts, or + on a mobile phone.

  2. Dial +377

    The country calling code for Monaco.

  3. Dial the national number

    Keep the number as provided until you confirm the international form with the recipient or your phone provider.

Whether a domestic prefix is included when calling Monaco internationally is not confirmed in this reference.

Full scope of this guidance

Whether a domestic prefix is included when calling Monaco internationally is not confirmed in this reference.

Example numbers

Example digits for each type of number, without the calling code or the exit code.

Number typeNational numberNational length
Fixed line991234568 digits
Mobile6123456788 digits or 9 digits
Toll-free type901234568 digits

Examples do not confirm assignment or reachability, and the types and lengths are not dialing rules. Source: Google libphonenumber.

Where this comes from

Country reference sources (4)

Catalog country/territory reference through exact nondeprecated P297; source entity facts only, no political/legal status or physical/telephone equivalence.

  • WikidataQ235 · Monaco · revision 2561865844reviewed 2026-10-30T20:34:07.220Z, 2026-10-30T20:56:52.174009+00:00Retrieved 2026-10-30T19:47:39.638Z. Retrieved 2026-10-30T20:53:42.463Z.
  • WikidataQ150 · French · revision 2561496129reviewed 2026-10-30T20:17:31.956ZRetrieved 2026-10-30T19:46:48.356Z.
  • WikidataQ4916 · euro · revision 2562478881reviewed 2026-10-30T20:17:31.956Z, 2026-11-01Retrieved 2026-10-30T19:46:48.356Z.
  • Natural Earth
  • Country referenceQ235 · Monaco. Revision 2561865844. Retrieved 2026-10-30T19:47:39.638Z; reviewed 2026-10-30T20:34:07.220Z.Licence
  • Descriptionmicrostate in Western Europe. Q235 · revision 2561865844. Retrieved 2026-10-30T20:53:42.463Z; reviewed 2026-10-30T20:56:52.174009+00:00.Description source
  • Capital: MonacoLinked English label: Monaco (Q235), revision 2561865844. Retrieved 2026-10-30T19:47:39.638Z; reviewed 2026-10-30T20:34:07.220Z. Statement Q235$a978022a-4770-762f-7d7b-12d278ecdf94, revision 2561865844, normal rank. No references attached in the selected revision.Statement Q235$a978022a-4770-762f-7d7b-12d278ecdf94
  • Official language: FrenchSource-reported official-language property; this is not a list of every spoken language. Linked English label: French (Q150), revision 2561496129. Retrieved 2026-10-30T19:46:48.356Z; reviewed 2026-10-30T20:17:31.956Z. Statement q235$B00DEE97-1204-4155-8767-BB74197FB35D, revision 2561865844, normal rank. 1 reference group attached in the selected revision.Linked English label: FrenchStatement q235$B00DEE97-1204-4155-8767-BB74197FB35Dq235$B00DEE97-1204-4155-8767-BB74197FB35D reference 1
  • Currency: euroSource-reported currency property; no currency code, symbol or legal-tender status is inferred. Linked English label: euro (Q4916), revision 2562478881. Retrieved 2026-10-30T19:46:48.356Z; reviewed 2026-10-30T20:17:31.956Z. Statement q235$33B49CE7-604A-481B-833D-2DF6A94DC074, revision 2561865844, preferred rank. Qualifications: P580: 1999-01-01 (day precision). No references attached in the selected revision. Displayed unit symbol: €. Separate retained P5061 source on Q4916, revision 2562478881. Retrieved 2026-10-30T19:46:48.356Z; reviewed 2026-11-01. Exact same unit symbol is explicitly retained on this currency entity, with complete Wikidata receipt/date. CLDR English standard form supports the display choice; no code/narrow fallback. No preferred-official-symbol claim. Selected symbol statement Q4916$e8c02b9e-4be4-12f3-61b5-914c94d81285, normal rank.Linked English label: euroStatement q235$33B49CE7-604A-481B-833D-2DF6A94DC074Unit symbol sourceSymbol source licence
  • Source-reported population: 2025 · Population of the selected source entity; this is distinct from map extent and telephone coverage.Statement Q235$f08cf20b-4911-4968-d0d6-74ef26b792b2, revision 2561865844, preferred rank. Qualifications: P585: 2025 (year precision). 1 reference group attached in the selected revision. Population is source-reported for 2025, with year precision. The selected population statement does not state a measurement method. Population of the selected source entity; this is distinct from map extent and telephone coverage.Statement Q235$f08cf20b-4911-4968-d0d6-74ef26b792b2Q235$f08cf20b-4911-4968-d0d6-74ef26b792b2 reference 1
  • MapAll 1 geometry parts and 1 rings retained. Exact selected Natural Earth country/map-unit extent; preserve source hierarchy and classification. No current legal-boundary or telephone-coverage assertion. Country overview from Natural Earth; capital positions from Wikidata may differ from the outline. The marked source position lies outside the retained land polygon. Source precision is not an accuracy radius. Country rings omitted: 0. Context rings omitted: 4. Monaco: the source position falls outside the retained outline; the location is approximate at this scale. Map extent: Monaco. Exact selected Natural Earth country/map-unit extent. No current legal-boundary or telephone-coverage assertion.Public-domain termsWikidata source position: Monaco
Land-border data (ODbL) (1)

Land-border list for the exact source country or territory record, at the stated dataset edition. Separate source identities are not combined. Use the exact source country and counterpart identities without metropole, calling-code, island, transport or boundary-segment inference. Land-border lists from the maintained mledoze/countries dataset at the stated repository edition. Its README defines the borders field as land borders, credits a borders contributor and Wikipedia for remaining data; this is not an official boundary survey. Exact country and territory identities remain separate. The source does not supply boundary segments, legal recognition findings or a per-country effective date. Retrieval is an observation date. This is a qualified source-edition enumeration, not a certification of complete physical borders in 2026. Contains information from mledoze/countries, made available under the Open Database License (ODbL) 1.0. Source-derived border assertions use that licence. Independent country information and government border evidence remain separate.

  • mledoze/countriesRepository commit fa4f62182d19ff4f8b325cde6387c9cd9d80955a Publication date as stated: not stated. Last modified date as stated: not stated. Retrieved: 2026-11-04T17:50:51.865Z.reviewed
  • Licence and transformationThe complete method of making every alteration, including all additional contents, is offered free of charge under ODbL section4.6(b). Source credit: mledoze/countries contributors, including @ancosen for borders data; the README identifies Wikipedia as the remaining-data source.Open Database License (ODbL) 1.0Transformation method (JSON)
Time-zone rules and display (1)

Supported calculations run from 2026-01-01T00:00:00Z until 2031-01-01T00:00:00Z. Zone names identify IANA representative locations; they do not locate a telephone number. The browser detects your device’s configured zone, which may differ from your physical location. Time rules: IANA tzdb 2026e. Location labels use its retained country tables. Times use the selected IANA entry; they are not a claim about every location in the country. The initial selection is a starting point; it does not confirm the capital’s time, country-wide time, or your location.

  • IANA Time Zone Databasetzdata2026eMonaco: calculation identifier Europe/Paris. Display identifier Europe/Monaco. Display source: zone.tab, line 257. Relation source: zone1970.tab, line 155. Alias Europe/Monaco → Europe/Paris (backward, line 236).
Calendar sources (3)

CLDR territory calendar-weekend convention; this is not national employment law, a universal employee days-off entitlement, or a guarantee that the pattern cannot change. CLDR49 supplemental.weekData.weekendStart.001=sat; weekendEnd.001=sun. Each endpoint uses the exact territory key when present, otherwise the explicit worldwide001 default documented by TR35 Week Data. No parent-territory rule or first-day-of-week inference is used. The start-to-end interval includes both endpoint weekdays and wraps across the end of the week. Numeric output is0Sunday through6Saturday. Copyright © 1991-2026 Unicode, Inc. Unicode License V3; full licence at https://www.unicode.org/license.txt. This is the Journal de Monaco Circular2025-8 list of paid and non-working days for2026, reproduced as a qualified official annual reference. The complete retained title, publication metadata, twelve table entries and surrounding body were personally read. It is not an independent consolidation of employment law or certification of every worker’s paid-leave entitlement, business closure or separately declared event. The circular is dated1October2025 and was published in Journal8768 on10October2025. The year covered is2026. These dates have different roles; no separate content-revision date is established and retrieval/cache timestamps are not legal publication evidence. The All Saints’ Day row prints nominal Sunday1November2026 and explicitly says it is postponed to Monday2November2026. The DTO contains only2November for that row;1November remains a source-only nominal observation. This explicit annual instruction is not generalized into a perpetual Sunday-substitution rule. Assumption Day remains the literal Saturday15August2026. No17August substitute, additional closure or automatic weekday shift is inferred. The retained source states no further conditional date or replacement instruction in this annual list. English names are reviewed translations of the French labels, not official English names. Sainte-Dévote is preserved as the proper name Saint Dévote in translation. The19November label refers to the Sovereign Prince; no unsupported independence or other holiday title is substituted. Through2026-12-31 means completeness of the twelve-row published2026 circular reference, with the explicit November movement. It does not certify every later decision, current-law amendment, actual employer closure or universal paid-leave entitlement. No2027 holiday date or perpetual calendar is supported. No weekend convention is derived from the annual holiday list. The separately admitted CLDR convention remains unchanged. Literal Gregorian civil dates are used without time-zone offsets, calculated Easter or library-generated dates. Maintained public-holiday library output for version 0.108; this is not government confirmation. Only the library's requested PUBLIC category and exact exporter mapping are included; other categories and unrequested subdivisions are excluded. The library's exact English labels and observed, substituted, and estimated annotations are retained. Missing annotation does not establish government confirmation. A maintained-library calendar reference does not guarantee future-law immutability, universal employee time off, or actual workplace closure. The package release is 2026-11-02T22:32:10.311079Z; this is a source release date, not a government publication or verification date. The maintained-library coverage bound reaches 2027-12-31 for the stated package-supported requested-year reference.

  • Unicode Consortium — CLDRPublication date as stated: not stated. Last modified as stated: not stated. Date metadata basis: Versioned49.0.0 source URL; retained JSON declares CLDR49 and Unicode16.0.0. Retrieval/review date is separate from dataset publication.. Source date qualification: The retained JSON file supplies version identifiers but no distinct publication or revision timestamp.. Source country scope: MC.reviewed
  • Journal de Monaco, Principality of MonacoPublication date: 2025-10-10. Publication date as stated: 10/10/2025. Last modified date: not stated. Date metadata basis: Printed Date de publication in Journal8768; the circular itself is dated1October2025 and covers2026.. Source country scope: MC.reviewed
  • Vacanza TeamPublication date as stated: 2026-11-02T22:32:10.311079Z. Publication date and time as stated: 2026-11-02T22:32:10.311079Z. Last modified as stated: not stated. Last modified date and time as stated: not stated. Publisher verification date as stated: not stated. Publication date: 2026-11-02T22:32:10.311079Z. Last modified date: not stated. Source date timezone: UTC. Date metadata basis: PyPI release metadata for python-holidays 0.108; package release time is distinct from the locally recorded package acquisition and export generation.. Source date qualification: No separate package source-update or government verification time is supplied by the retained release metadata.. Source country scope: MC. Licence: MIT.reviewed
  • Calendar weekendCalendar weekend days: Sunday, Saturday. Source-backed CLDR calendar convention using its explicit own-territory/default resolution; no public-holiday dates, statutory work schedule or historical 2026–2027 legal coverage is inferred. Source locator: CLDR49 supplemental.weekData.weekendStart.001=sat; weekendEnd.001=sun..Unicode Consortium — CLDR
  • Public holiday2026-01-01: New Year’s Day. Source name (fr): Le jour de l’An. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row1.Journal de Monaco, Principality of Monaco
  • Public holiday2026-01-27: Saint Dévote’s Day. Source name (fr): Le jour de la Sainte‑Dévote. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row2.Journal de Monaco, Principality of Monaco
  • Public holiday2026-04-06: Easter Monday. Source name (fr): Le Lundi de Pâques. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row3.Journal de Monaco, Principality of Monaco
  • Public holiday2026-05-01: Labour Day. Source name (fr): Le jour de la Fête du Travail. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row4.Journal de Monaco, Principality of Monaco
  • Public holiday2026-05-14: Ascension Day. Source name (fr): Le jour de l’Ascension. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row5.Journal de Monaco, Principality of Monaco
  • Public holiday2026-05-25: Whit Monday. Source name (fr): Le Lundi de Pentecôte. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row6.Journal de Monaco, Principality of Monaco
  • Public holiday2026-06-04: Corpus Christi. Source name (fr): Le jour de la Fête Dieu. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row7.Journal de Monaco, Principality of Monaco
  • Public holiday2026-08-15: Assumption Day. Source name (fr): Le jour de l’Assomption. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row8.Journal de Monaco, Principality of Monaco
  • Public holiday2026-11-02: All Saints’ Day. Source name (fr): Le jour de la Toussaint. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. The source explicitly prints nominal Sunday1November and postponement to Monday2November2026. Only the expressly moved2November is projected; the nominal1November remains source-only. No general substitution rule is inferred. Source locator: Circular2025-8, annual2026 table row9; nominal1November explicitly postponed to Monday2November.Journal de Monaco, Principality of Monaco
  • Public holiday2026-11-19: Sovereign Prince’s Day. Source name (fr): Le jour de la Fête de S.A.S. le Prince Souverain. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row10.Journal de Monaco, Principality of Monaco
  • Public holiday2026-12-08: Immaculate Conception. Source name (fr): Le jour de l’Immaculée Conception. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row11.Journal de Monaco, Principality of Monaco
  • Public holiday2026-12-25: Christmas Day. Source name (fr): Le jour de Noël. Name basis: Reviewed English translation, not an official English name. Role: Source-listed public holiday. Literal date in the circular’s paid/non-working annual list. No substitute date, general worker entitlement or other closure is inferred. Source locator: Circular2025-8, annual2026 table row12.Journal de Monaco, Principality of Monaco
  • Public holiday2026-01-27: Saint Devote's Day. Source name (en): Saint Devote's Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2026; it is not government confirmation. Source locator: python-holidays 0.108; 2026 PUBLIC category output; exact emitted label “Saint Devote's Day”..Vacanza Team
  • Public holiday2026-05-01: Labor Day. Source name (en): Labor Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2026; it is not government confirmation. Source locator: python-holidays 0.108; 2026 PUBLIC category output; exact emitted label “Labor Day”..Vacanza Team
  • Public holiday2026-05-25: Pentecost Monday. Source name (en): Pentecost Monday. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2026; it is not government confirmation. Source locator: python-holidays 0.108; 2026 PUBLIC category output; exact emitted label “Pentecost Monday”..Vacanza Team
  • Public holiday2026-11-01: All Saints' Day. Source name (en): All Saints' Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2026; it is not government confirmation. Source locator: python-holidays 0.108; 2026 PUBLIC category output; exact emitted label “All Saints' Day”..Vacanza Team
  • Public holiday2026-11-19: Prince's Day. Source name (en): Prince's Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2026; it is not government confirmation. Source locator: python-holidays 0.108; 2026 PUBLIC category output; exact emitted label “Prince's Day”..Vacanza Team
  • Public holiday2027-01-01: New Year's Day. Source name (en): New Year's Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “New Year's Day”..Vacanza Team
  • Public holiday2027-01-27: Saint Devote's Day. Source name (en): Saint Devote's Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Saint Devote's Day”..Vacanza Team
  • Public holiday2027-03-29: Easter Monday. Source name (en): Easter Monday. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Easter Monday”..Vacanza Team
  • Public holiday2027-05-01: Labor Day. Source name (en): Labor Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Labor Day”..Vacanza Team
  • Public holiday2027-05-06: Ascension Day. Source name (en): Ascension Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Ascension Day”..Vacanza Team
  • Public holiday2027-05-17: Pentecost Monday. Source name (en): Pentecost Monday. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Pentecost Monday”..Vacanza Team
  • Public holiday2027-05-27: Corpus Christi. Source name (en): Corpus Christi. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Corpus Christi”..Vacanza Team
  • Public holiday2027-08-15: Assumption Day. Source name (en): Assumption Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Assumption Day”..Vacanza Team
  • Public holiday2027-08-16: Assumption Day (observed). Source name (en): Assumption Day (observed). Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. The library identifies this label/date as observed; its nominal and observed rows are preserved as separate source assertions when both are emitted. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Assumption Day (observed)”..Vacanza Team
  • Public holiday2027-11-01: All Saints' Day. Source name (en): All Saints' Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “All Saints' Day”..Vacanza Team
  • Public holiday2027-11-19: Prince's Day. Source name (en): Prince's Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Prince's Day”..Vacanza Team
  • Public holiday2027-12-08: Immaculate Conception. Source name (en): Immaculate Conception. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Immaculate Conception”..Vacanza Team
  • Public holiday2027-12-25: Christmas Day. Source name (en): Christmas Day. Name basis: English name quoted from the source. Role: Source-listed public holiday. This source assertion is emitted by maintained library version 0.108 from its PUBLIC category for 2027; it is not government confirmation. Source locator: python-holidays 0.108; 2027 PUBLIC category output; exact emitted label “Christmas Day”..Vacanza Team
Country and calling-code metadata (2)

Country metadata confidence: Maintained library. Last reviewed: 2026-10-02.

This is a static dialing reference, not an authoritative global numbering dataset.

It does not validate live phone numbers, identify a person or current number owner, confirm a current carrier, locate a device or provide an exact location, assess spam reputation, or support reverse lookup.