Message too long (&4 char. entered, only &3 permitted) for device &1/&2

What causes this issue?

The text you have entered contains &V4& characters.
However, the equipment with serial number &V1& / device category &V2&
can only contain &V3& characters.

System Response

The message cannot be sent.

How to fix this error?

Use a maximum of &V3& characters.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.