Is it achievable to route a dynamic URI with prefixed character?
So from reading your updated answer and looking at the other question you mentioned I would assume you are trying to create prefixed dynamic links that don't conflict with your routing.

For example site.com/about would link to your about page and site.com/#about would load up your custom template.

Problem

The problem with using a # for your trigger is that really this should be used for linking to internal sections on a page and with the above site.com/#about would actually just link to your index page and if you had a &lt;div&gt; with an id of about you'd find the scroll position at that div, so I think using a # is going to give you a lot of headaches.

Solution

Perhaps use the @ sign? if it's good enough for twitter to use then I don't think you'll have many problems using it.

So, in your config/routes.php you would have:

return array(
 '(?P&lt;username&gt;\@\w+)' =&gt; '_someCustomTemplate',
);


This will match anything starting with an @, assign it to username a variable in your template and load it up, I tested on the Happy Lager install and it worked like a charm, /about goes to the about page /@about goes to my custom template

So in your custom template you could have the following:

{# This will get rid of the @ #}
{% set username = username|replace({'@': ''}) %}

{% set user = craft.users.username(username) %}


If you want to change the trigger to something else, just change @ in the route expression and then in the replace filter, but that should do the trick for you and avoid conflicts!

on a side note, I replaced @ with a # and it didn't work, just went to the home page