Standards for drawing chemical molecules
As it happens, there are a set of quite involved documents from the "IUPAC Chemical Nomenclature and Structure Representation Division".

There's a list here, but to avoid later link-rot, they are currently:


Jonathan Brecher Graphical representation of stereochemical configuration (IUPAC Recommendations 2006) 2006, Vol. 78, Issue 10, pp. 1897-1970
Richard M. Hartshorn, Evamarie Hey-Hawkins, René Kalio and G. Jeffery Leigh: Representation of configuration in coordination polyhedra and the extension of current methodology to coordination numbers greater than six (IUPAC Technical Report)
2007, Vol. 79, Issue 10, pp. 1779-1799
W. Mormann and K.-H. Hellwich: Structure-based nomenclature for cyclic organic macromolecules (IUPAC Recommendations 2008) 2008, Vol. 80, Issue 2, pp. 201-232
Jonathan Brecher: Graphical representation standards for chemical structure diagrams (IUPAC Recommendations 2008) 2008, Vol. 80, Issue 2, pp. 277-410
Andrey Yerin, Edward S. Wilks, Gerard P. Moss and Akira Harada: Nomenclature for rotaxanes and pseudorotaxanes (IUPAC Recommendations 2008) 2008, Vol. 80, Issue 9, pp. 2041-2068