5. Depending on the purpose of the map or according to national traditions,
at any scale level, further qualifiers may be added optionally. They may be
additional principal qualifiers from further down the list and not already used in
the soil name, or they may be supplementary qualifiers. They are placed using
the above-mentioned rules for supplementary qualifiers. If two or more optional
qualifiers are used, the following rules apply:
a. the principal qualifiers are placed first, and of them, the first applicable
qualifier is placed first, and
b. the sequence of any supplementary qualifiers added is decided by the soil
scientist who makes the map.