";" (semicolon) actually indicates cost, under PSCT rule. While "," (comma) is effect only.
On old card text, it's harder to distinguish since "," (comma) is used for both cost and effect. Hence the PSCT, to make it different and easier to spot.
Before ":" (colon) = activation condition
Before ";" (semicolon) = cost
Before "," (comma) = effect
But like I said, it's unfortunately harder to distinguish with cards that are not reprinted yet in real life TCG with PSCT, since that means they still have the old version text that uses comma on everything.
Two things to note: Not EVERYTHING before a semi-colon is a cost (though they're never effects, but just the same, declaring card names, etc. isn't a cost), just stuff you do upon activation. And second, this wording scheme only applies to activation costs. MAINTENANCE costs don't use a semi-colon. (Spiritual Energy Settle Machine won't trigger Dark Worlds for example.)