title: Why can't a branch name contain the 'space' char?
body: <p>I tried:</p>
  
  <pre><code>git branch "MyProj/bin/ ignored"
  </code></pre>
  
  <p>and received:</p>
  
  <pre><code>fatal: 'MyProj/bin/ ignored' is not a valid branch name.
  </code></pre>
  
  <p>The <a href="http://www.kernel.org/pub/software/scm/git/docs/git-branch.html" rel="noreferrer">git-branch</a> man page points to the <a href="http://www.kernel.org/pub/software/scm/git/docs/git-check-ref-format.html" rel="noreferrer">git-check-ref-format</a> man page to get the actual rules for a valid branch name.</p>
  
  <p>Sure enough, the reason for the above fatal error appears to be the inclusion of a space character.</p>
  
  <p>Any idea why, in this day and age, spaces are still excluded from a branch name (I would have expected it in ancient CVS, for example, but Git?)</p>
  
  <p>What could be valid technical reasons for that?</p>