, imposes a variety of open-meeting and disclosure requirements on entities meeting the definition of ??advisory committee.?? As relevant here, such a committee is an entity or ??subgroup ??? , which is ??? established or utilized by the President, ??? exclud[ing] ??? any committee ??? composed wholly of full-time, or permanent part-time, [federal] officers or employees.?? 5 U. S. C. App. ??2(B)(i