In the section of smb.conf(5) that describes the "default case"
parameter, the structure of the sentences and lack of punctuation
leaves them open to a number of interpretations.

Suggested wording for this paragraph is as follows:

    default case = upper/lower
    
        controls what the default case is for new filenames (ie. files
        that don´t currently exist in the filesystem). Default
        _lower_. IMPORTANT NOTE: As part of the optimizations for
        directories containing large numbers of files, the following
        special case applies.  If the options _case_sensitive_=_yes_,
        _preserve_case_=_No_, and _short_preserve_case_=_No_ are set,
        then the case of _all_ incoming client filenames, not just new
        filenames, will be modified.  See additional notes below.