Document Structuring Conventions

Document Structuring Conventions (DSC) is a set of standards for <a href="/facts/PostScript/h2XwbcmC">PostScript</a>, based on the use of <a href="/facts/Comment_(computer_programming)/Q8hHFq8h">comments</a>, 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 <a href="/facts/Turing_completeness/73goop44">Turing-complete</a> 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 <a href="/facts/Print_spooler/fPbanPPu">print spooler</a> to have the ability to rearrange the pages for printing, or for a <a href="/facts/Page_layout_program/gUPtzSnH">page layout program</a> to find the <a href="/facts/Bounding_box/oFHL8bxI">bounding box</a> 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 <a href="/facts/Portable_Document_Format/C9Mn1vYL">PDF</a> 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 <a href="/facts/Preprocessor/arTRL5RG">preprocessing</a> <a href="/facts/Directive_(programming)/RsozxGG0">directives</a> 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 <a href="/facts/Encapsulated_PostScript/MxugDBHI">Encapsulated PostScript (EPS)</a>: 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 <a href="/facts/Adobe_Illustrator_Artwork/r9klm86Y">Adobe Illustrator Artwork</a> file format.

Document Structuring Conventions open-in-new

Document Structuring Conventions