http://content.themat.com/forms/Rulebook.pdfMentions freestyle, greco and folkstyle - it looks like "tight fitting"
Competitors dress
Chapter 1 Article 5
https://www.iahsaa.org/wrestling/2012-13%20Wrestling%20Rules%20Book%20for%20IA.pdfNFHS Wrestling Rules for 2012/13 season
Rule 4, Section 1 Article I "Wrestlers Uniform"
It looks like tight fitting with 1 manufacturing label/logo
That is my understanding