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Slash-delimited category names

The spec says about categories:

<category> sub-element of <item>

<category> is an optional sub-element of <item>.

It has one optional attribute, domain, a string that identifies a categorization taxonomy.

The value of the element is a forward-slash-separated string that identifies a hierarchic location in the indicated taxonomy. Processors may establish conventions for the interpretation of categories. Two examples are provided below:

<category>Grateful Dead</category>

<category domain="">MSFT</category>

You may include as many category elements as you need to, for different domains, and to have an item cross-referenced in different parts of the same domain.
But what if an element itself uses the forward slash, for example: Hydrogen/potassium ATPase, which -- it's been pointed out --  is a valid Library of Congress Subject Heading?

We think the simplest solution will be to escape the forward slash in that element, so for example:

Hydrogen%2fpotassium ATPase

We invite users of taxonomies in which this issue arises to comment on whether this will, in fact, work acceptably.