Marking small bits of text

If you want to conditionalize just part of the text of an element, you can use the phrase element to mark the text. For example, if the only difference is one sentence within a paragraph, you can mark it this way:

<para>To open a file, select File Open. <phrase os="win">The default
configuration lists share drives such as E: as well as the C: hard 
<phrase os="linux">The default configuration lists NFS-mounted filesystems 
as well as local filesystems.</phrase> Choose the file from the list.</para>

Note these features of using phrase: