The IPv4Mask scalar type is an IPv4 netmask represented as UTF-8 character sequences. Accepted formats are:

Short notation (number of leading zeros in binary). i.e: 32, 24, 8.
Long notation (octets separated by dots). i.e: 255.255.255.255, 255.255.255.0, 255.0.0.0.

scalar IPv4Mask