Deciphering technical linguistics!

Hi, lovely linguaphiles :)

A friend of mine asked me a linguistics realed question, and I'm not entirely sure on the answer myself. I was wondering whether you'd be able to help us decipher exactly what this short passage from a Grammar of Marathi actually means:

'among the systems of intraclausal argument marking, cross-reference by bound pronominals is the most important: prefixes and clitics'


We're a little confused as to whether he's stating that the language marks case on arguments by prefixes and clitics, or whether he means that agreement markers on the verb are prefixes and clitics? Or, in fact, something completely different!

Thank you so much in advance if you can shed any light on this!
:)