Show Jumpers Attire in the ring

Did anyone else ever question whether those EIS/sun shirts actually counted as “collared shirts” when they first became trendy? For a while I didn’t wear one during the weekday jumper classes in fear of the steward telling me I needed a collared shirt…I just don’t think the zipper tops really look like collars. Even if you attempt to fold them down. They look neat and tidy either way and I am guilty if wearing one during the week, but just a thought.