MS Teams menus use 'dial patterns' to match numbers dialed. These patterns use regular expression (regex) strings. For example, the regex string ^2\d{2}$ matches any three-digit number beginning with a 2.

• MS Teams uses dial patterns in dial plans to match numbers dialed by a user and apply a number translation.

• MS Teams uses dial patterns in voice routes to match the number on outgoing calls to the routes for the call.

For additional information, refer to:

• https://docs.microsoft.com/en-us/dotnet/standard/base-types/regular-expression-language-quick-reference

• https://support.microsoft.com/en-us/topic/6ea76427-0892-4237-b024-10b418dcb05e

• https://regex101.com/ - This site provides a useful tool for testing the operation of your own regex strings.