Hull number vs. sail number

[GeeDee]

I picked up a 1985 Catalina 22 a few weeks ago and I'm sure this must have been asked before, but I want to confirm the hull number vs. the sail number. I'm going to get a new mainsail and I've seen some posts suggesting a 1 should be added to the sail ahead of the hull number.
My hull shows 3003, should my sail show that, or 13003?
Thanks!
Newbie Catalina 22 owner

 

[Richard19068]

As far as I know unless you are going to get a number assigned by an association, such as US sailing, or race in a particular class, it really doesn't matter. You can put on whatever number you want or no number at all. You could use your birthday, graduation date, wedding anniversary... If you want to use your hull number there is no requirement to put a 1 in front of it.