[Asterisk-Users] CALLERIDNUM::3 do not working on 1.2.1

[Kevin P. Fleming]

Shidan wrote:

> But, when you imply "that's your problem because it wasn't
> documented", I would really like to know where this official
> documentation is apart from reading the source code. Most successful
> Asterisk based operations are novel and creative hacks, not structured
> formulas that follow any official documentation.

Substring manipulation has always been documented in doc/README.variables.