http://wiki.oasis-open.org/office/Replace_complex_RE's_with_EBNF

... which points to some meeting minutes from 2008:

<quote>

• Points are integers in ODF, but floating-point in SVG:
  The ODF schema currently allows only integer values, while SVG allows
  floats. The point data type currently is described by a regular
  expression. Extending the regular to support floats would result in very
  long and unreadable expressions. The question (and open action item) is
  to find an alternative way to describe the data type, for instance an
  EBNF grammar. This may apply to other data types as well. This action
  item shall be divided into two, one for the specific points data type,
  and one for the more general question how to avoid unreadable regular
  expressions.
  </quote>

... and Patrick's mail:

https://lists.oasis-open.org/archives/office/200806/msg00006.html