Editing Document Structuring Conventions (section)

'''Document Structuring Conventions''' ('''DSC''') is a set of standards for [[PostScript]], based on the use of [[comment (computer programming)|comment]]s, that specifies a way to structure a PostScript file and a way to expose that structure in a machine-readable way. A PostScript file that conforms to DSC is called a ''conforming document''.

The need for a structuring convention arises since PostScript is a [[Turing completeness|Turing-complete]] programming language. There is thus no guaranteed method — short of actually printing the document — to do things like determining how many pages long a given document is or how large a given page is, or how to skip to a particular page. The addition of structure, with DSC comments exposing that structure, helps provide a way for, e.g., an intelligent [[print spooler]] to have the ability to rearrange the pages for printing, or for a [[page layout program]] to find the [[bounding box]] of a PostScript file used as a graphic image. Collectively, any such program that takes PostScript files as input data is called a ''document manager''.

In order for a PostScript print file to properly distill to [[Portable Document Format|PDF]] using Adobe tools, it should conform to basic DSC standards. 

Some DSC comments serve a second function, specifying a way to tell the document manager to do certain things, like inserting a font or other PostScript code (collectively called ''resources'') into the file. DSC comments that serve this second function are more akin to [[Preprocessor|preprocessing]] [[directive (programming)|directive]]s and are not purely comments. Documents using those kinds of DSC comments require a functioning document manager to come out as intended; sending them directly to a printer will not work.

DSC is the basis for [[Encapsulated PostScript|Encapsulated PostScript (EPS)]]: EPS files are documents that conform to the  DSC standards with further restrictions.

The set of DSC comments can be expanded by a mechanism called the Open Structuring Conventions, which, together with the EPS specification, form the basis of early versions of the [[Adobe Illustrator Artwork]] file format.