Check with the Captain before you log it as PICUS unless your not going to bother getting them to sign it.
Some Captains get very very upset if you presume to log PICUS.
Most (myself included) don't give a toss. And some company's policy is not to allow you to log it because thier pay structure give's you a rise when you get your ATPL.
Check it out first, saves having a grumpy captain.