Syntactic significance of dot

[Richard Shann]

I've come across some (working) scheme code whose meaning I can't
unravel. The problem is there is a "." character whose significance
eludes me. The guile reference doesn't index this character, and I can
only find references to it in writing literal pairs.
But I'm sure someone experienced would recognize what this could be (the
dot occurs on the eleventh line):

  (define (ignatzek-format-exception
           root
           exception-markup
           bass-pitch
           lowercase-root?)

    (make-line-markup
     `(
       ,(name-root root lowercase-root?)
       ,exception-markup
       .
       ,(if (ly:pitch? bass-pitch)
            (list (ly:context-property context 'slashChordSeparator)
                  (name-note bass-pitch #f))
            '()))))

Richard Shann