1 /AFTER
/AFTER (D) /AFTER[=directory-spec] Specifies that LSE should insert the directory or directories indicated into the list of source directories in back of the directory you specify as the value on the qualifier. If you do not specify a directory-spec value, LSE adds the directory or directories to the end of the list. If you do not specify either the /AFTER qualifier or the /BEFORE qualifier, LSE replaces the entire directory list.
2 /BEFORE
/BEFORE /BEFORE[=directory-spec] Specifies that LSE should insert the directory or directories indicated into the list of source directories in front of the directory you specify as the value on the qualifier. If you do not specify a directory-spec value, the directory or directories are added at the front of the list. If you do not specify either the /BEFORE qualifier or the /AFTER qualifier, LSE replaces the entire directory list.