Below I copied the appropriate paragraphs from pg 6 of the link you provided. I think the instruction you listed from HomeAway above is good suitable advice but is not very accurate in listing what the requirement reads.
(e) The name and phone number of the local contact for each transient accommodation shall be included in any transient accommodation contract or written rental agreement and shall be prominently posted in the transient accommodation. The local contact shall reside on the same island as the transient accommodation, and shall meet all other requirements under subsection (a). Any person or entity who wilfully fails to supply information required under this subsection shall be subject to the penalties under section 231-35; provided that a person or entity shall not be subject to any term of imprisonment or probation under section 231-35.
In the above paragraph, I don't see any requirement to provide this information to our guests, except in the Rental Agreement and to provide it within our accommodations. Note that e-mail address is not a requirement.
(f) The registration identification number issued pursuant to section 237D-4 shall be provided on a website or by online link and displayed in all advertisements and solicitations on websites regarding transient accommodations for which the registration number is issued.
The above paragraph does not say how or where this information shall be displayed -- only that it must be provided and displayed.
Maybe you could make a distinction between what is required and what is recommended.