Help with ISO standard inRFid

I was going throgh IC spec, from different manufacturers, I was looking for ISO15693 protocol , even red wiki, but still have doubts of whether different tags [different manufactures] have any specific data protocl of their own.

Like for TI, RI- R6C-001A data sheet mentions 'ISO15693-2 [eg: TAG-it HF-I]'

TRH0033M mentions ISO15693 [tag-it,I-code,etc]

so does this mean I can not use TI reader IC to reader I-CODE tags?

Any info on this is really helpful.