QuoteI read that some robo call systems will auto-remove your number from their list if it senses a FAX tone.
Seems logical from the robo call system point of view.
I've tested some more and run into a problem which I think has been noted before. This:
sp1($1>$1)} equates to sp1(cid>target)}
$1 is an internal variable containing the value of the caller number of the inbound call.
According to the Obihai documentation sp1($1>$1)} should work. In fact the first $1 does not work and has to be a literal string. The second $1 does work.
Using softphones I got this to work:
sp1('fraudsquad'>$1)}
Normal DECT phones etc won't display "fraudsquad", but maybe a robo call system will record it! Alternatively, you could use a local police or fraud squad number and use this format:
sp1(12345678901>$1)}
12345678901 will be sent as CallerID to the number that made the original call.
Anyhow, there's a few ideas. As QBZappy pointed out, the incoming CallerID may be bogus as we often see CallerIDs such as "100", "1000" etc.