- use a font other than the one pre-set in the 3GPP styles;
- use the underline attribute, as this causes confusion when revision marks are used;
- put more than one space after a full stop;
- precede comma (,), semicolon (;), colon (:), full stop (.), question mark (?) or exclamation mark (!) by spaces;
- use spaces in place of tabs when indentation/alignment is required; this can cause text to be misaligned;
- use footnotes or end-notes;
- unnecessarily use capital letters.