It seem O2 may not be the only one up to this: Headers that can be used to identify the end user: Header name What it means x-drutt-portal-user-msisd

It seem O2 may not be the only one up to this: Headers that can be used to identify the end user: Header name What it means x-drutt-portal-user-msisdn The mobile phone number. x-h3g-msisdn the phone number. x-imsi: The imsi number. Identifies the end user. x-msisdn The end users phone number x-wsb-identity End users phone number x-wte-msisdn: Indicates that the value is a phone number. Does not look like that... x-nokia-imsi: Imsi value x-nokia-alias The end users phone number. encrypted. x-nokia-msisdn: The users phone number in plain text. x-up-calling-line-id: End user identifier Gleaned from: http://mobiforge.mobi/developing/blog/useful-x-headers?dm_switcher=true http://mobiforge.mobi/developing/blog/useful-x-headers?dm_sw... Edit: fixed the formatting.