factotum<p>I found a post earlier today, suggesting basically the same thing, with one interesting difference.</p><p><span class="h-card" translate="no"><a href="https://neurodifferent.me/@lapingvino" class="u-url mention">@<span>lapingvino</span></a></span> suggests to prefix the code characters with &quot;geo&quot;, for hashtags like <a href="https://c.im/tags/geo9F4MG9" class="mention hashtag" rel="tag">#<span>geo9F4MG9</span></a> - which is nice because it hints at the hashtag being some sort of location reference even for users not yet aware of this idea.</p><p>Just to brainstorm a bit, possible alternatives could be:<br /><a href="https://c.im/tags/geo_9F4MG9" class="mention hashtag" rel="tag">#<span>geo_9F4MG9</span></a> (underscore for readability)<br /><a href="https://c.im/tags/local_9F4MG9" class="mention hashtag" rel="tag">#<span>local_9F4MG9</span></a> (&quot;local&quot; to highlight the local nature)<br /><a href="https://c.im/tags/at_9F4MG9" class="mention hashtag" rel="tag">#<span>at_9F4MG9</span></a> (short!)</p>