Yes you can apply for full registration if you are a Principal who has previously been probated in a restricted setting but you may not sign the Principal sector of your own form.
If you are a Principal in the school where you completed your 50 day service, please get the Chair of the Board of Management to confirm the details on the form. They should cross out Principal and insert BOM Chair. If you completed your service in another school please get the Principal of the school where you completed your service to confirm the details on the form.