In Kerberos, a(n) is an identification card for a particular client that verifies to the server that the client is requesting services and that the client is a valid member of the Kerberos system and therefore authorized to receive services.

ticket

Explanation:

In Kerberos, a ticket  is an identification card for a particular client that verifies to the server that the client is requesting services and that the client is a valid member of the Kerberos system and therefore authorized to receive services.

i would first let him be aware that a cover letter is official and confidential and it requires a proper formatting so that the employer doesn't have hard time when going through it. he should write it in paragraphs of about two to four sentences and use proper grammar a , spelling and proper punctuation. i will also advice him not to be emotional and not also to use images.then base his attention to the details of the job described and not other things. that is he be specific to the responsibilities and to the employers requirements. on this he should make sure that the letter reflects how good he is for the requirements detailed by the employer

the letter should not be too long nor too short.