Many sites don't support the plus in email addresses ("+" = comment, supported e.g. by GMail). Not so funny if the register process works but the login or passw

Many sites don't support the plus in email addresses ("+" = comment, supported e.g. by GMail). Not so funny if the register process works but the login or password reset features are broken. Example: a site let me register and login with the plus. But resetting the password was hard, I had to escape the plus to get it working.