Does Drupal distinguish types of error messages? In D7, under Configuration &gt; Development &gt; Logging and errors you can set "Error messages to display" to "none".

However, I would think users should still be able to see form error messages, for example when they don't fill out a required field.

Are there different 'types' of 'error messages'?
This setting is for server errors, the drupal form errors will still be shown. 

Here is some more information on this topic:
https://www.drupal.org/node/1036982