OMF251 Specification

Hi Gentel Man,
I'm developing a debugging tool for MCS-51, I need to read the omf file generated by Keil 5.
I get a copy of OMF51 from keil.com, but it's too old, many new record's types are not list in the OMF51 specification.
Can I get a copy of OMF2(OMF-251) specification?
I need your help!
Any suggestion will be welcome.