If you capitalize "instruction manual" it would be implied that you are showing a title, such as a document titled "Instruction Manual." If it is not capitalized, then you are simply making a statement about that object. For example: "You can find the information you need in the instruction manual" -This is a statement about where you can find the information you need "You can find the information you need in the Instruction Manual" -This is implying that you can find the information in the document called "Instruction Manual." I hope this helps you out. Let me know if you need more clarification.

General rules for using capitalization: *The first letter of each major word in a title of a book, movie, article.* ( "Harry Potter" "Clockwork Orange" ) For example "There are directions inside of the Ford Instruction Manual." > Ford Instruction Manual is a very specific item. However, if someone was saying "Can you look in the instruction manual for information on replacing the lens." the words instruction manual would not be capitalized because it is a general item. A few more reasons to use capitalization. *The first word in a sentence. *The first word in a quote. *The pronoun I (As in I am going for a walk) *The first letter of a proper noun (A specific name) *The first letter of months, days, and holidays. *The first letter of nationalities, religions, races of people and languages.

You would capitalize the words "Instruction Manual" when it is the title of the document. This is a proper noun, an official title or name. If the words are not capitalized, it could refer to any general instruction manual. These might have an other title or name, which would be capitalized.