# Allowed characters

Some characters are not allowed in the Subject Distinguished Name (DN) and in the limitation of use (LoU) defined in the certificate.
For this reason some characters in the firstName and lastName defined in the [DisposableHolder](/products/leandisposable/enterprise-documentation/developer-documentation/api-references/data-objects#disposableholder) are not allowed.

These characters are not allowed:

| Characters | Not Allowed |
|  --- | --- |
| ` | X |
| ? | X |
| ! | X |
| & | X |
| ; | X |
| $ | X |
| ~ | X |