You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Eton_College

Context:
The opposite of a Show Up is a "Rip". This is for sub-standard work, which is sometimes torn at the top of the page/sheet and must be submitted to the boy's housemaster for signature. Boys who accumulate rips are liable to be given a "White Ticket", which must be signed by all his teachers and may be accompanied by other punishments, usually involving doing domestic chores or writing lines. In recent times,[when?] a milder form of the rip, 'sign for information', colloquially known as an "info", has been introduced, which must also be signed by the boy's housemaster and tutor.

Question:
Who must sign a White Ticket?

all his teachers