Hotels receive many inquiries for meetings, some of which may fall over the same dates. The first group to inquire over a set of dates has the 'First Option' hold on those dates. If another group comes along and is interested in the same dates, they can request a second option contract and, once signed, the hotel will approach the first option group and give them a short window (typically 48 hours) to either:
1. Sign the first option contract
2. Release the dates to the second option group.
This is a very delicate dance among the three parties. As a planner, being "second optioned" is never fun, but is necessary to ensure rooms and space are sold as efficiently as possible by the hotel. Your best defence is to ensure you're moving swiftly through the decision and contract signing process and to always keep the hotel engaged through out. If the hotel is confident in your decision and knows clearly when to expect a signed contract, they're less likely to start the dance in the first place.