I imagine it was just a way to identify it as an important term. SHINRA and SOLDIER are both all capped as well.
Shin-Ra actually isn't all caps in almost any of the places it appears.
And SOLDIER is an acronym.
Standing for what? It's a rubbish acronym.
Forgot that Shin-Ra is weird though. Still, it would make sense to have the two diametrically opposed groups of SOLDIER and AVALANCHE capped. Has more gravitas like that, too.