This enhancement request arose in the sequence of issues #14156 and #19309

Currently eZ Publish automatically (and silently) converts non alphabetic characters, found when parsing for siteaccess names, into underscore characters. This behavior cannot be overridden and has proved useful for most use cases over the years.
Nevertheless, there are some use cases where this handling is not desired.

For instance, when your site's contents are widely referred in external sources, and the maintenance of these external links are handled by manual input, then you might not wish to allow some referrals to link to your siteaccess as "site-eng", while others name it as "site:eng" and others, still, have ":site+eng!".
If you allow this, then you might get penalized in relevance counters of your content by indexing services such as google.

Easy to implement, and with no impact on the current usability of eZ Publish, would be too add a ini setting where users could specify they don't wish to have this automatic character replacing active.

An extend enhancement would be to allow the character replacing to occur, but to return HTTP status 301 everytime such operation takes place.