23.0423GPPCompression algorithm for text messaging servicesRelease 17TS
Keyword Dictionary ID 0 (decimal)
This Keyword Dictionary ID has the special meaning that no Keyword Dictionary is defined (or therefore enabled) and the value of bit 1 of octet 1 of the CH is always to be interpreted as zero.
Keyword Dictionary ID >0 (decimal)
No other Keyword Dictionaries are defined and all other values are reserved.