I'm sorry I took so long to reply to this. I read it, and had some things run through my mind, and lost my focus and had to go to a tournament and........blah, blah, blah.... Again, I'm truly sorry.
The alert chart advises us that "all jump raises in or out of competition except a WEAK jump raise after a PASS by RHO." I believe this applies, as long as there is nothing conventional about the 3H/3S call. A conventional bid artificially carries a meaning not necessarily related to the denomination named. If you are using 3H/3S as part of a raise structure, differentiating between different lengths of support, this would be considered a "treatment", not a convention, and would not require an alert.
I am including an excerpt from the ACBL Alert Pamphlet here:
"To ensure full disclosure, however, at the end of the auction and before the opening lead declarers are encouraged to volunteer to explain the auction (including available inferences). I believe this passage applies here.
Let me clarify slightly what Bill said. The alert chart indicates that the following *require no alert*: "5. All jump raises in or out of competition except a WEAK jump raise after a PASS by RHO."
I would certainly be confused with Bill's statement if I simply read it without any context. :)