Agents are able to lock the commission on RFPs so the venues can't change the commission rate when they respond using the RFP response form.
This isn't something we tell the agents about but some of them (BTE) know about it and have it switched on.
It looks like this on the RFP response form, note the padlock icons:
If the highlighted box is ticked the commission will be locked on every RFP
Do not advise agents of this function