Commodity codes - definition of 'of cotton'

Hi, not sure if anyone can help please?
To be ‘of cotton’ does a garment have to be 100% Cotton or could it say be 95% Cotton 5% Elastane.
Thanks for your help

See section note 2 to section XI:

    1. (A) Goods classifiable in Chapters 50 to 55 or in heading 5809 or 5902 and of a mixture of two or more textile materials are to be classified as if consisting wholly of that one textile material which predominates by weight over any other single textile material.
  • When no one textile material predominates by weight, the goods are to be classified as if consisting wholly of that one textile material which is covered by the heading which occurs last in numerical order among those which equally merit consideration.

Most likely your garment thus would be classifiable as “of cotton”. Please note that such garments which have layers e.g. of plastics etc. attached may have to be classified otherwise.