>> you can't have volunteer resources run the video
>> equipment for you. You need a professional crew.
> Is there a more specific description of the specific authority,
> wording, and legislative intent for this, please?
It's not an actual law, but the SF Bay Area is fairly heavily unionized
in this sector, so most convention centers and major hotels in the SF
Bay Area have agreements that specify what kinds of activity require
union labor under which circumstances. So you'd need to look at those
agreements rather than at the city code. Normally the venue can provide
more detail about this in their information package for prospective
conference organizers, and it varies venue-to-venue. For venues actually
owned by the city of SF (like Moscone Center), their general agreement
with IATSE over audiovisual services (at least as of 2014) is here:
It's not just USA. We have similar issues in Australia too. Many "enterprise agreements" (as we call them) specifically prevent volunteers doing work that is part of the duties of a paid staff member.
And of course any venue can impose rules on you as part of the contract of using their premises, whether there is any law or any union agreement underpinning it. They may just do it to protect themselves in relation to workplace safety. A volunteer may not know they have to cover a cable snaking across the floor with gaffer tape (for example). They may bring their own electrical cable without a recent "test tag" on it. Etc.