Which document is NOT required to display the contractor's CSLB license number?

Explanation

§7030.5 is the licence-number section and it names three places: all construction contracts, subcontracts and calls for bid, and all forms of advertising as the registrar prescribes. (b), (c) and (d) are all on that list — a subcontract is there expressly, and a bid is what a call for bid produces. An ordinary purchase invoice to a materials supplier is none of them, which makes (a) the exception the question wants: it is a buying document rather than an offer of contracting services, and the supplier is not the person the disclosure exists to protect. Do not confuse §7030.5 with §7030(a), which requires something different in the same contracts — the CSLB notice, in at least 10-point type, telling the consumer that a complaint about a patent act or omission must be filed within four years of the alleged violation and one about a latent structural defect within ten. §7027.1(a) polices the advertising side of the same idea.