This code system http://hl7.org/fhir/contact-point-system defines the following codes:

Code Display Definition
phone Phone The value is a telephone number used for voice calls. Use of full international numbers starting with + is recommended to enable automatic dialing support but not required.
fax Fax The value is a fax machine. Use of full international numbers starting with + is recommended to enable automatic dialing support but not required.
email Email The value is an email address.
pager Pager The value is a pager number. These may be local pager numbers that are only usable on a particular pager system.
url URL A contact that is not a phone, fax, pager or email address and is expressed as a URL. This is intended for various institutional or personal contacts including web sites, blogs, Skype, Twitter, Facebook, etc. Do not use for email addresses.
sms SMS A contact that can be used for sending a sms message (e.g. mobile phones, some landlines).
other Other A contact that is not a phone, fax, page or email address and is not expressible as a URL. E.g. Internal mail address. This SHOULD NOT be used for contacts that are expressible as a URL (e.g. Skype, Twitter, Facebook, etc.) Extensions may be used to distinguish "other" contact types.
<status value="active"/> <experimental value="false"/> <date value="2023-03-26T15:21:02+11:00"/> <publisher value="HL7 (FHIR Project)"/> <contact> <telecom> <system value="url"/> <value value="http://hl7.org/fhir"/> </telecom> <telecom> <system value="email"/> <value value="fhir@lists.hl7.org"/> </telecom> </contact> <description value="Telecommunications form for contact point."/> <jurisdiction> <coding> <system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/> <code value="001"/> <display value="World"/> </coding> </jurisdiction> <caseSensitive value="true"/> <valueSet value="http://hl7.org/fhir/ValueSet/contact-point-system"/> <content value="complete"/> <concept> <code value="phone"/> <display value="Phone"/> <definition value="The value is a telephone number used for voice calls. Use of full international numbers starting with + is recommended to enable automatic dialing support but not required."/> </concept> <concept> <code value="fax"/> <display value="Fax"/> <definition value="The value is a fax machine. Use of full international numbers starting with + is recommended to enable automatic dialing support but not required."/> </concept> <concept> <code value="email"/> <display value="Email"/> <definition value="The value is an email address."/> </concept> <concept> <code value="pager"/> <display value="Pager"/> <definition value="The value is a pager number. These may be local pager numbers that are only usable on a particular pager system."/> </concept> <concept> <code value="url"/> <display value="URL"/> <definition value="A contact that is not a phone, fax, pager or email address and is expressed as a URL. This is intended for various institutional or personal contacts including web sites, blogs, Skype, Twitter, Facebook, etc. Do not use for email addresses."/> </concept> <concept> <code value="sms"/> <display value="SMS"/> <definition value="A contact that can be used for sending a sms message (e.g. mobile phones, some landlines)."/> </concept> <concept> <code value="other"/> <display value="Other"/> <definition value="A contact that is not a phone, fax, page or email address and is not expressible as a URL. E.g. Internal mail address. This SHOULD NOT be used for contacts that are expressible as a URL (e.g. Skype, Twitter, Facebook, etc.) Extensions may be used to distinguish "other" contact types."/> </concept> </CodeSystem>