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BaseType Element

SharePoint 2003

Every list in a Web site based on Microsoft Office SharePoint Portal Server 2003 inherits its schema from a base type. The BaseType element defines the default schema (for example, the fields) that all lists derived from the base type must contain.


  Image = "URL"
  Title = "Text"
  Type = "Number">


ImageSets the image used by a list base type in the Lists page (_layouts/viewlsts.htm). However, all SharePoint list definitions (such as for Announcements, Events, and so on) provide their own images so that, in practice, this attribute is never used.
TitleThe name of the base type.
TypeUnique ID for the base type. The following values are possible for built-in base types:
  • 0 — Custom List
  • 1 — Document Library
  • 2 — not used
  • 3 — Discussion Forum
  • 4 — Surveys
  • 5 — Issues List

Element Relationships

Parent ElementsChild Elements
BaseTypes MetaData


The fields defined in a base type may not be deleted from a derived list without breaking the list (for example, a document library will not function without the file name column), although fields may be added to the list.


This example from the file ONET.XML defines the discussion forum base type, in other words, the fields that all discussion forums must have. You can create other discussion forums with additional fields; however, all discussion forums must include the fields defined in the following base type.

<BaseType Title="Discussion Forum" Image="_layouts/images/itdisc.gif" Type="3">
         <Field ColName="tp_ID" Type="Counter" Name="ID" ReadOnly="TRUE" PrimaryKey="TRUE" DisplayName="ID"></Field>
         <Field Type="Text" Name="Title" DisplayName="Subject" Required="TRUE" ></Field>
         <Field ColName="tp_Modified" ReadOnly="TRUE" Type="DateTime" Name="Modified" DisplayName="Modified" StorageTZ="TRUE"></Field>
         <Field ColName="tp_Created" ReadOnly="TRUE" Type="DateTime" Name="Created" DisplayName="Posted At" StorageTZ="TRUE"></Field>
         <Field ColName="tp_Author" ReadOnly="TRUE" Type="User" List="UserInfo" Name="Author" DisplayName="Posted By" ></Field>
         <Field ColName="tp_Editor" ReadOnly="TRUE" Type="User" List="UserInfo" Name="Editor" DisplayName="Modified By" ></Field>
         <Field ColName="tp_Version" Hidden="TRUE" ReadOnly="TRUE" SetAs="owshiddenversion" Type="Integer" Name="owshiddenversion" DisplayName="owshiddenversion"></Field>
         <Field ColName="tp_Ordering" Hidden="TRUE" ReadOnly="TRUE" Name="Ordering" Type="Threading" DisplayName="Ordering"></Field>
         <Field ColName="tp_GUID" ReadOnly="TRUE" Hidden="TRUE" Type="Guid" Name="GUID" DisplayName="GUID"></Field>
         <Field ColName="tp_HasAttachment" Type="Attachments" Name="Attachments" DisplayName="Attachments"></Field>
         <Field ColName="tp_ModerationStatus" ReadOnly="TRUE" Type="ModStat" Name="_ModerationStatus" DisplayName="Approval Status" Hidden="TRUE" CanToggleHidden="TRUE" Required="FALSE">
         <Field ReadOnly="TRUE" Type="Note" Name="_ModerationComments" DisplayName="Comments" Hidden="TRUE" CanToggleHidden="TRUE" Sortable="FALSE"></Field>
         <Field ReadOnly="TRUE" Name="ThreadID" Hidden="TRUE" Type="Guid" DisplayName="Thread ID"></Field>
         <Field ReadOnly="TRUE" Type="Computed" Name="Threading" Hidden="TRUE" DisplayName="Subject" DisplayNameSrcField="Title" AuthoringInfo="(threaded)" >
         <Field ReadOnly="TRUE" Type="Computed" Name="ThreadingNoIndent" DisplayName="Subject" DisplayNameSrcField="Title" AuthoringInfo="(linked to item with edit menu)" >
         <Field Name="Body" RichText="TRUE" Type="Note" DisplayName="Text" Sortable="FALSE" NumLines="10"></Field>
         <Field ReadOnly="TRUE" Type="Computed" Name="Edit" Sortable="FALSE" Filterable="FALSE" DisplayName="Edit" AuthoringInfo="(link to edit item)" >
         <Field Name="InstanceID" DisplayName="InstanceID" ColName="tp_InstanceID" ReadOnly="TRUE" Hidden="TRUE" Type="Integer" Min="0" Max="99991231" Filterable="TRUE" Sortable="TRUE"></Field>
         <Field ColName="tp_ItemOrder" Name="Order" DisplayName="Order" Type="Number" Hidden="TRUE"></Field>