PGACheckSum(5) on Linux

The text 0b21f7a6bd06, as Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze), Debian 5.0 (Lenny) shipped it. The page shows this text now.

maps a string to a number to be used a verification check PGA_DATATYPE_USER is not supported.