Tags as RSS categories?

I followed Oatmeal's way of doing it here

Thank you, that's useful, but not quite what I'm looking for. What I would like is that the tags of an entry will be declared in the feed.rss file as categories, as in:

<category>tag1</category>

<category>tag2</category>

and so on. As I understand it, that would take advantage of a Feedmail feature that would let specifically my readers who subscribe via email filter based on tags.

I just edited the rss template and added the following lines inside the <item> tag:

{{#tags.length}}{{#tags}}
      <category>{{name}}</category>
{{/tags}}{{/tags.length}}

Although, now I want to check if it's a good standard to have multiple categories for one item on RSS feed.

How are you planing to use that?

Thank you, this is working!

Although, now I want to check if it's a good standard to have multiple categories for one item on RSS feed.

I wondered about that too. Based on checking a couple of feeds I subscribe to, it certainly seems to be a common practice to have multiple categories though.

How are you planing to use that?

It's just to take advantage of a feature that Feedmail (an RSS-to-email service) has. When users subscribe to my blog via email, this let's them exclude update for tags they don't want. E.g., I publish in both English and German, and this will let non-German speakers filter out German posts. Or posts about topics they're not interested in. And I imagine it might also be useful for certain RSS readers that let you filter based on category.

Ah, yes, you did mention Feedmail in your question, that sounds fun!