Bounding index designators of string.
An ipv6-address object or
trim-whitespace is a boolean specifying that leading and trailing whitespace characters may be ignored. Note that the address itself must not contain any whitespace. The default value of trim-whitespace is
In addition, the address may be followed by a '%' character and a scope ID. If the scope ID is a string of decimal characters, it is read as a decimal number, otherwise it is taken as-is. The address may also be followed by a '/' and a prefix length in decimal format. The result ipv6-address object remembers the prefix length and prints it when the object is printed, but it does not affect the address otherwise.
If the syntax of the string string is correct,
parse-ipv6-address constructs the ipv6-address object and returns it. It does not perform any address resolution.
LispWorks User Guide and Reference Manual - 20 Sep 2017