Access Control List (ACL) filter (command)

• Access-list number    Identifies the access list using a number in the range 100 – 999 (extended IP ACL) 2000 – 2699 (expanded IP ACLs)
• Deny    Denies access if the conditions are matched
• Permit    Permits access if the conditions are match
• Remark    Indicates whether this entry allows or blocks the specified address. Could also be used to enter a remark.
• Protocol    Name or number of an internet protocol. Common keyword include ICMP IP, TCP or UDP
• Source    Number of the network or host from which the packet is being sent
• Source-wildcard    Wildcard bit to be applied to source
• Destination    Number of the network or host to which the packet is being sent
• Destination wild-card    Wildcard bit to be applied to the destination
• Port    The decimal number or name of a TCP or UDP port
• Established     For the TCP protocol only; indicates an established connection.
• Operator   
• lt (less than) 
• gt (greater than)
• eq (equal)
• neq (not equal)

Source: http://www.orbit-computer-solutions.com/Access-Control-Lists-%28ACL%29.php