[This is preliminary documentation and subject to change.]
| Common-Name=Telephone-Number | Admin-Display-Name=Telephone-Number |
| Admin-Description=Telephone-Number | Object-Class=Attribute-Schema |
| Attribute-ID=2.5.4.20 | OM-Syntax=64 |
| Attribute-Syntax=String(Unicode) | LDAP-Display-Name=telephoneNumber |
| Multi-valued | System-Only=FALSE |
| Mapi-ID=\x8012 | |
| Range 1 to 32 | |
| Schema-ID-GUID={bf967a49-0de6-11d0-a285-00aa003049e2} | Comment=used by Exchange |