Not necessary for the below:
2) The Buttons
Buttons for a Fred Perry Polo Shirt, with couple of distinctive exceptions, will always be the same colour as the primary colour of the rest of the top. For example, if the polo shirt is mostly red but with a white collar and cuffs, the colour of the buttons will always be red. There are one or two exceptions to this, though. One of the collaborations Fred Perry did with renowned Belgian designer Raf Simons used buttons of opposing colour. In addition there are a few limited edition styles coming from Japan that have differently coloured buttons. However, nearly all Fred Perry Polos will have the same colour.
Furthermore, every button will need the text 'Fred Perry' visibly embossed into it.
3) The Tag
The content label at the back of the inside of the garment is an area that is often overlooked by te counterfeit gangs, even though it can contain many clues hinting towards the authenticity of the product. This tag area is generally hard to miss and is printed with the word 'Fred Perry' in a very significant, crystal clear sans-serif typeface, complimented with the garments size and the typical Fred Perry wreath logo. Fake items are usually generally designed in some sort of wiry, spaced out typeface alongside with a really bad attempt of a wreath logo.
There is an urban myth that says that shirts with a Green tag are always fake, however this is not always the case. If the shirt that you are looking at was made in the past couple of years, the tag will probably be black or blue; but not green. However, if the shirt was made in the 90s there is a very good chance it will be green. A Fred Perry polo shirt with a green tag will either be old and/or fake, but it will never be new and genuine.