+The first tag in the file represents the root of the record. It should
+contain the name of the application profile that the record belongs
+to. If the profile is not already known, the system will look for the
+profile description in the file <tt/profile.abs/, where <tt/profile/
+is the name of the given profile.
+
+The following is a typical beginning of a GILS record:
+
+<tscreen><verb>
+<gils>
+ <Title>
+ USGS server for Gopher. See available linkage to begin.
+ <Acronym>
+ USGS Gopher
+ &etago;Acronym>
+ &etago;Title>
+
+ ...
+
+&etago;gils>
+</verb></tscreen>
+
+<it>
+NOTE: The indentation of the elements shows above is applied solely
+to clarify the relationships between the elements. Any unnecessary
+whitespaces are ignored by the retrieval system.
+</it>
+
+The construction above describes the first element of a GILS record;
+the title. The title is structured into a &dquot;well-known&dquot;
+element, and an additional element with a local string tag,
+<bf/Acronym/. Since the
+tag <bf/Title/ appears in tagsetG, which is included by the GILS
+tagset, this is a well-known element. The tag <bf/Acronym/ appears
+nowhere in the tagsets for the GILS profile, so it is treated as a
+locally defined string tag by the system.
+
+<sect1>Types of Input Elements
+
+<p>
+Currently, X types of input elements are recognized:
+
+<itemize>
+<item>The root element, which associates the record with a given
+schema.
+
+<item>The normal tagged element, which corresponds either to a
+specific tag from the tag sets referenced by the schema, or to a
+locally defined string tag (implicitly).
+
+<item>An inclusion element, for inserting data from an external source
+(a file, typically) into the record.
+
+<item>An element data unit, which corresponds to normal data.
+
+<item>A variant-component.
+</itemize>
+