Clarify: RegExp scf meaning

[Jack-Works]

There are two different wordings when mentioning the Simple Case Folding:

Canonicalize:

If the file CaseFolding.txt of the Unicode Character Database provides a simple or common case folding mapping for ch, ...

scf:

the Simple Case Folding (scf(cp)) definitions in the file CaseFolding.txt of the Unicode Character Database

The Unicode file mentioned above writes:

# The status field is:
# C: common case folding, common mappings shared by both simple and full mappings.
# F: full case folding, mappings that cause strings to grow in length. Multiple characters are separated by spaces.
# S: simple case folding, mappings to single characters where different from F.
# T: special case for uppercase I and dotted uppercase I
#    - For non-Turkic languages, this mapping is normally not used.
#    - For Turkic languages (tr, az), this mapping can be used instead of the normal mapping for these characters.
#      Note that the Turkic mappings do not maintain canonical equivalence without additional processing.
#      See the discussions of case mapping in the Unicode Standard for more information.
#
# Usage:
#  A. To do a simple case folding, use the mappings with status C + S.
#  B. To do a full case folding, use the mappings with status C + F.
#
#    The mappings with status T can be used or omitted depending on the desired case-folding
#    behavior. (The default option is to exclude them.)

The wording in Canonicalize is clear, it is C + S. I'm not sure if scf also refers to C + S (by the Usage comment), or it's just S (by the status field).