What is the significance of prefix "19:" in Microsoft Teams Channel id?

Question

In Microsoft Teams Channel the channel id has prefix "19:" what is the significance of this prefix and is it always going to be same?

The format of channel id is- "19:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX@thread.skype"

Answer 1

The "19:" it is just a type that defines the kind of object for Microsoft infrastructure internally (channel or team). There are other prefixes, like "28:xxxxx" for example for a bot, "29:xxxx" for a user, etc.

I would avoid relying on this prefix, though, and just use the whole ID as a string without trying to parse it.