The content of this element specifies a Unicode character that is displayed repeatedly at the position where the element occurs. The character specified is repeated as many times as possible, but the total resulting string shall not exceed the given cell content area.
Fill characters may not fill all the available space in a cell. The distribution of the remaining space is implementation dependent.
To chapter "16.27.1 General" add the sentence:
Data styles shall specify at most one <number:fill-character> element.