Intec Argus 3u plus Manual page 128

15 Configuration
beginning of a call number is treated as a valid character.
Example:
02351/9970-45 is entered as 023519970#45
If the "# " is at the end of a number, when the
number is later dialed it will be done without CGPN
or OAD. This is important for some PBXs.
130 ARGUS 3u plus/3u NT