title: Why should tags be space-delimited?
body: <p>I'm working on a Web application that uses tags like Stackoverflow tags. I've noticed that a lot of sites that use tags make them space-delimited, which disallows a tags like...</p>
  
  <pre><code>"favorite recipes"
  </code></pre>
  
  <p>Instead they enforce this...</p>
  
  <pre><code>"favorite-recipes" | "favorite_recipes" | "FavoriteRecipes"
  </code></pre>
  
  <p>If the tags were comma-delimited, an item could have a set of tags like...</p>
  
  <pre><code>"cats, birds, favorite recipes, horses"
  </code></pre>
  
  <p>I have to decide on the policy for my app.</p>
  
  <p>I guess I like the idea of space-delimited, but if my users aren't programmers they might be more comfortable with the familiar idea of commas denoting a list.</p>
  
  <p>Why are comma-delimited tags unusual? Is there a major downside to them?</p>