/CONTENT=substring
       /ENV_FROM=substring
       /SUBJECT=substring

    The /CONTENT, /ENV_FROM, and /SUBJECT qualifiers are used to
    specify the substrings for which to search. Any combination of
    /CONTENT, /ENV_FROM, and /SUBJECT may be specified. However, only
    one of each may be used. When a combination of such qualifiers
    is used, the /MATCH qualifier controls whether the qualifiers
    are interpreted as further restrictions (/MATCH=AND), or as
    alternatives (/MATCH=OR).