Resource Type, also known as Content Type, is an ESRI-specific classification of documents and a required element of a metadata document being published to an ArcIMS Metadata Service.
If the metadata document doesn't have a resource type element present or the resource type is invalid, when publishing metadata to an ArcIMS Metadata Service using the GIS Portal Toolkit, the GPT first tries to determine the proper resource type by scanning for certain pieces of information in the metadata. If GPT finds the pieces of information that it is looking for, a given resource type may be assigned. Otherwise, the metadata document is assigned a default resource type, usually Other Documents or Offline Data.
If the metadata document does have a resource type element defined, whose value is within the accepted list of values, the metadata document is assigned the resource type that is specified.
In some cases, however, certain resource types require additional information to be present in the metadata. For instance, classifying a document to be the Downloadable Data type, requires that a valid URL be present in the metadata pointing to the location of the data download. For documents of the Live Data and Maps type, information about the map server and map service has to be present.
When a metadata document is published, if the resource type specified is one of the types that require checks for additional pieces of information to be present, it is possible that the checks fail. In those cases, the document is assigned a default resource type, rather than the one originally specified in the metadata document.
For full details on the checks against certain resource types, and which default values are applied in certain cases, refer to Chapter 9 "Publishing Metadata" in the GPT 3.1 User Guide. A link to the GPT 3.1 User Guide can be found below in Related Information.