Add 'family_description' or allowing custom field for the 'ip_families' table

The ‘ip_families’ table in my case contains abbreviated codes which are nice and short but not very verbose.
It would be nice to have a second field like ‘family_description’ explaining the codes.
Adding ‘ip_families’ to the ‘custom field’ allowed table list would make this possible.
THX

[size=10]Last Update: 05.01.2016[/size]