Answer: I figure you're talking about chord notation, right? Some letters above a tune?

In pop and jazz, slashes are often used to indicate a chord inversion. "B/F#" would refer to a B major triad with the F# in the bass. That's what in music school would be known as a second-inversion major triad. D7/A is also a second-inversion chord, but this time it's a D7 chord with its fifth, A, in the bass.

But then you get to Abm/Eb. Once again that's a second-inversion triad: Ab minor this time, with the Eb in the bass. Only odd thing is what business an Ab minor triad has keeping company with B major and D7. Those chords don't belong in the same key. I'm not saying it can't be there, but it might attract suspicion. Maybe you're drawing these examples from different songs, of course.