If I intended to play 18 holes, am I able to post a 9-hole or 10-17 hole score?

Score Posting partial round

Yes, regardless of the number of holes the round is set up for, you will be able to post a score as long as at least 9-hole scores on a rated side have been entered. If the round was set up for 18 holes and you attempt to post the score while leaving some hole scores blank, you will be prompted with a warning message to confirm if you want to post your score (yes, you do!). For example, if you completed 13 holes and had to leave your round, you would be leaving holes 14-18 blank so the WHS procedure of "expected score" kicks in to calculate an 18-hole equivalent in your record.