Certain matters require approval or other actions by the ACL Exec:
Review and issue Call for Bids for the conference (properly, this is performed by the Exec, who traditionally appoints the Vice President to do so). Review the conference bids and accept one of them. This necessarily includes selecting the Local Arrangements Chair, the location, and the date of the conference. See ACL policy on who can hold major programmatic positions at ACL conferences.
Identify remaining key organizers, notably the General Chair and the Program Co-chairs (see criteria for selecting the General Chair and the PC Co-chairs). Sign a contract with venue(s) (hotel, conference center, etc.). Traditionally, this is done by the ACL Treasurer. Set approximate registration deadlines and costs. Review and approve the sub-chairs suggested by the conference General Chair, such as the tutorial chair, the workshop chair, the publications chair, the student research workshop chair, etc Review and approve the Area Chairs suggested by the Program Co-chairs. Review and accept the tutorials and workshops selected by the appropriate chairs. Request occasional updates on the conference budget and current state of affairs from the General Chair. Review the status of local organization and request updates from the Local Arrangements Chair.