Greetings of the day Biostars!

Can anyone tell me what are different types of crosses we can give in 'genotypes program' ? According to manual it can be included by giving '-t' option. 'CP', 'DH', 'F2', 'BC1' and 'GEN' are the currently supported map types. What do these abbreviation means?

Tool's official website: http://catchenlab.life.illinois.edu/stacks/

Thanks in advance! :)