BGP: AS private number check

Hi All, According to RFC1930, the AS number 64512 to 65535 are reserved for private, I cannot find the implementation for checking private AS number in BIRD, anybody know it or it's lost in BGP ? RFC1930 10<https://tools.ietf.org/html/rfc1930.html#section-10>. Reserved AS Numbers The Internet Assigned Numbers Authority (IANA) has reserved the following block of AS numbers for private use (not to be advertised on the global Internet): 64512 through 65535 Thanks Arvin