T4
SMS, MMS, 10DLC
Text, media, and the registration names. 3 lessons. Each lesson cites the pages that were opened, and marks the rest confirm.
SMS, and the 160-character line
T4-R10
Wikipedia says SMS is a text messaging service that lets mobile phones exchange short text messages, typically over cellular networks.
MMS and the media a page will store
T4-R11
Wikipedia says MMS sends multimedia content to and from a mobile phone and extends SMS so messages can be longer than 160 characters.
10DLC is a name on the compliance pages
T4-R12
Twilio's compliance page that opened is titled Programmable Messaging and A2P 10DLC.
Sources and go deeper
Opened 2026-10. A row marked confirm has no link, because that page was not verified.
- RFC. RFC 3261, SIP last checked 2026-10
- Wikipedia. Session Initiation Protocol last checked 2026-10
- Wikipedia. Platform as a service, Communications platform as a service section last checked 2026-10
- Confirm. Release-specific menus for this track. confirm. Not opened as a single checklist. last checked 2026-10