[asterisk-dev] Strange code in chan_sip.c

[Vadim Lebedev]

In Asterisks 1.6.1.10  at line 7997 in chan_sip.c

contains following code:

       if (!sscanf(token, "%30" SCNd64, &rua_version)) {
 

What is this:   "%30" SCNd64   ?

Any ideas?
Thanks
Vadim