Programmer's Guide > Programming and Scripting Techniques > Line Numbering in Arbortext Editor and Arbortext Publishing Engine > Line numbering application building reference > The Layout file and document type > The common entities
  
The common entities
The following entities are declared in the Layout DTD, and are used for declaring attributes that point back into the document or store dimensions.
<!ENTITY % oid "CDATA" > <!--vdid,df,genno-->
<!ENTITY % offset "NMTOKEN" > <!--zero based offset-->
<!ENTITY % dimen "CDATA" > <!--dimension in pt, e.g 1.25-->