[Asterisk-Users] Definitive CallerID Format and anonymous?

[Jay Milk]

All,

I use various IAX providers to terminate my outbound calls.  I set the
caller-ID to one of several DIDs, based on the called number.  There
doesn't seem to be any rhyme or reason as to what the called user sees,
however.

Calls to most cell-phones show *exactly* the number I submit.
Calls to land-lines sometimes show, other times not.
Calls to other voip-providers most often show, but sometimes don't.

I'm currently only setting CID as a ten-digit number.  Has anyone on
this list tested caller-id delivery with various services?  Is there
*one* usable format (i.e. 1+10, or "+1"+10), or does it vary from
provider to provider?

Secondly, I've been having a difficult time hiding my CID information
from callees.  Not setting it will sometimes deliver the extension ID
(logically); setting it to a blank string will sometimes deliver random,
even invalid numbers.  My best bet so far has been to simply set it to
0000000000.  Better options?