|Metadata, conditional processing, and indexing / Condition (or select) attributes|
You can have more than one value for a select attribute. The different values are stored in the one attribute, separated by spaces.
In many cases, you may want to apply more than one value to a metadata attribute. For example, a paragraph may relate to audiences of both admin and manager.
<p audience="admin manager">The installation...</p>
Obviously, then, individual values of metadata attributes must not contain spaces.