GAO dismissed a protest as untimely where the protester waited until after its bid was rejected to challenge a patent ambiguity in the solicitation. The Army Corps of Engineers issued an invitation for bids (IFB) that included standard FAR clauses indicating the procurement was being set aside for small businesses, but the IFB did not include other regulatory requirements for set asides, such as the NAICS code or size standard. The Army rejected the protester's low bid because the company was other than small, and the company protested. The protest decision is a stark reminder that a company that competes under an ambiguous solicitation cannot wait until after