PRO Records when Collaborating and Publishing Question..

[Tunesmith]

Hello,
I have a couple questions...

I just registered a song with ASCAP and added the other writer who is with BMI..so both our IPI numbers are there and the work has a registration number.

My question is, does my co-writer have to do the same on his BMI account or will the registration I did of the song reflect on his BMI account? I would assume there should only be 1 registration/work ID number of the song?

My other question is, if there is no publisher at the time of registration, should I self publish? Or does one leave it open for the Library (or future publisher) to be assigned as publisher when signed? It is 50% of the royalties so I'm concerned about saying "no publisher"

I don't mean to sound too naive..I am self published with my music CD's but the library business is new to me.

Thank you in advance!

Best,
Linda C