body: Are there any restrictions on using content included under the [D&D System Reference Document](http://media.wizards.com/2016/downloads/DND/SRD-OGL_V5.1.pdf)?
  
  
  As a hypothetical, if I were writing a fantasy book, could I freely throw in a Yrthak or Gray Render with no restrictions?
  
  
  I'm thinking of publishing a supplement for another RPG under their Open Game License that includes creatures in the D&D SRD, which has all relevant information in its first pages.
  
  
  
title: Am I allowed to freely use content included in the D&D SRD?