Represents the form-of-use values for RDB$CHARACTER_SETS
    information table.

    Value      Name          Description

    0          FIXED_OCTET   Fixed octet
    1          MIXED_OCTET   Mixed octet with DEC_KANJI style
                             encoding
    2          FIXED_NO_UP   Fixed octet, no uppercasing allowed
    3          MIXED_SS2     As in MIXED_OCTET plus <SS2> as
                             introducer to alternate single octet
                             encoding
    4          FIXED_UP_G1   Fixed octet, uppercasing only 7-bit
                             characters
    5          MIXED_SS3     As in MIXED_SS2 plus <SS3> as introducer
                             to alternate double octet encoding
    6          FIXED_OTHER   Fixed octet, other
    7          MIXED_C2CB    As in MIXED_OCTET plus hex 'C2CB' as
                             introducer to alternate double octet
                             encoding
    9          MIXED_TAG     Mixed octet with leading tag, compound
                             string
    11         MIXED_SHIFT   Mixed octet with coding table shifted;
                             for example, SHIFT_JIS