Yes, the CT number for documented vessels is just for their computer system.
For documented vessels there is also two notices. One at the top of the page under "Important Notice" after a note that says "Make sure you pay all local property taxes
due and fulfill any requirements listed below."
The "requirement listed below" is stated as "Letter Coast Guard Auxillary".
Down at the bottom of the page, there is a notice stating "The following issues must be resolved before you renew:" Then "Document(s) Required."
No other explination about either of these cryptic items. I called the DMV as soon as I got the notice and eventually got through to a very nice lady who said that those two notices, along with the CT number assigned, were all just part of their new computer system. Just send in your registration fee with the stub and you will get your new registration and sticker. She said your US documentation
number will be listed on your registration, not the assigned CT number (not that it matters to me what number they put on my registration, it's their document).
She did say that I should send the renewal stub and fee to the address listed on the renewal stub at the bottom of the page: 60 State St. Weathersfield, for me. Do not send it to the location on the pre-printed envelope, so use your own envelop and write out the address that is on the renewal stub. She said it would take longer if you sent it to the address on the pre-printed envelope.
I half expect this will not work and I'll get my registration rejected because I didn't send them "Letter Coast Guard Auxillary". I doubt Coast Guard Auxillary knows anything about this.
We'll see I suppose.