A more thorough explanation:

A testing clause is a legal term used in Scots law to refer to the clause at the end of a formal written instrument or deed that authenticates it according to the forms of law.

Traditionally, the testing clause includes the following information:

• The name and address of the writer
• The number of pages in the instrument
• Any alterations or erasures
• The names and addresses of the witnesses
• The name and address of the person who penned the instrument
• The date and place of signing

For example, a will may include a testing clause that confirms the identity of the testator (the person making the will), the witnesses, and the date and place of signing. This clause helps to ensure that the will is legally valid and can be enforced according to the laws of Scotland.

Another example of a testing clause can be found in a contract, where the clause may include information about the parties involved, the terms of the agreement, and the date and place of signing. This clause helps to establish the legal validity of the contract and can be used as evidence in court if necessary.