Hamlet doesn’t bother with a sign off. He doesn’t say “Yours truly” or “Sincerely” or “Til tomorrow” or “thine as thou usest him” or “Thine evermore, most dear lady, whilst this machine is to him” as he wrote to Ophelia or “He that thou knowest thine” as he wrote to Horatio. He’s just like, “Hamlet.” Not “Prince of Denmark” or “your nephew” or even “That guy you tried to have killed but failed to.”