Difference between fields InternalName and StaticName in Sharepoint

If you work with Sharepoint you probably faced already with fields xml definitions and probably know that field has 3 different names:

• Title/TitleResource (display name)
• InternalName
• StaticName

Title is quite obvious: this is the user friendly display name. But what about InternalName and StaticName? In most cases they are the same but there are situations when they may be different. In this post I will show such situation.

Let’s create new site content type TestContenType and add new Text site column with long name. Length of the field name should be greater than 32 symbols. We won’t use spaces and non-latin symbols for simplicity. In my test I used name TextFieldWithVeryVeryLongInternalName which has 37 symbols:

If we will check schema xml of this content type and this field we will see something like that (I used Sharepoint Online client browser for checking xml schema’s):

(below it will be explained why field link TextFieldWithVeryVeryLongInternalName is highlighted)

Here is content type’s xml definition:

<ContentType ID="0x0100CD88C368C93C7D4D89E7D60F478C2BF0" Name="TestContentType" Group="Custom Content Types" Version="2">
    <Folder TargetName="_cts/TestContentType" />
    <FieldRefs>
        <FieldRef ID="{c042a256-787d-4a6f-8a8a-cf6ab767f12d}" Name="ContentType" />
        <FieldRef ID="{fa564e0f-0c70-4ab9-b863-0177e6ddd247}" Name="Title" Required="TRUE" ShowInNewForm="TRUE" ShowInEditForm="TRUE" />
        <FieldRef ID="{947d0169-b8c1-417b-aba9-891357b7d4d5}" Name="TextFieldWithVeryVeryLongInternalName" />
    </FieldRefs>
</ContentType>

and here is field’s xml definition:

<Field Type="Text"
       DisplayName="TextFieldWithVeryVeryLongInternalName"
	   Required="FALSE"
	   EnforceUniqueValues="FALSE"
	   Indexed="FALSE"
	   MaxLength="255"
	   Group="Custom Columns"
	   ID="{947d0169-b8c1-417b-aba9-891357b7d4d5}"
	   SourceID="{d754b6da-6897-4a5a-8d73-49abb52cb20a}"
	   StaticName="TextFieldWithVeryVeryLongInternalName"
	   Name="TextFieldWithVeryVeryLongInternalName"
	   Version="1"
	   Customization="" />

As you can see both in content type and field xml definition all names (Title, InternalName, StaticName) are set to original value “TextFieldWithVeryVeryLongInternalName”. It gives us first important finding: site columns may have InternalNames which length is greater than 32 symbols.

Now let’s create new list and add our TestContentType to this list. As you probably know in this case Sharepoint creates new List content type which has the same name as original site content type but is not equal to it – it inherits original site content type instead. First of all content type id will be longer: it will inherit original content type id and add guid after “00”:

{parent content typeid}00{guid without dashes}

i.e. in our case content type id of list content type will be:

0x0100CD88C368C93C7D4D89E7D60F478C2BF000{guid without dashes}

(see below). But this is not the only difference. Let’s see what happened with FieldLink on our long name field:

See the difference with the site content type? List content type has field link with exactly 32 symbols: TextFieldWithVeryVeryLongInterna. Let’s check xml definitions of list content type and list field:

<ContentType ID="0x0100CD88C368C93C7D4D89E7D60F478C2BF0006A178989905DF348B5D2BD81EF28374A" Name="TestContentType" Group="Custom Content Types" Version="1">
    <Folder TargetName="TestContentType" />
    <Fields>
        <Field ID="{c042a256-787d-4a6f-8a8a-cf6ab767f12d}"
			Type="Computed"
			DisplayName="Content Type"
			Name="ContentType"
			DisplaceOnUpgrade="TRUE"
			RenderXMLUsingPattern="TRUE"
			Sortable="FALSE"
			SourceID="http://schemas.microsoft.com/sharepoint/v3"
			StaticName="ContentType"
			Group="_Hidden"
			PITarget="MicrosoftWindowsSharePointServices"
			PIAttribute="ContentTypeID"
			FromBaseType="TRUE">
            <FieldRefs>
                <FieldRef Name="ContentTypeId" />
            </FieldRefs>
            <DisplayPattern>
                <MapToContentType>
                    <Column Name="ContentTypeId" />
                </MapToContentType>
            </DisplayPattern>
        </Field>
        <Field ID="{fa564e0f-0c70-4ab9-b863-0177e6ddd247}"
			Type="Text"
			Name="Title"
			DisplayName="Title"
			Required="TRUE"
			SourceID="http://schemas.microsoft.com/sharepoint/v3"
			StaticName="Title"
			FromBaseType="TRUE"
			ColName="nvarchar1"
			ShowInNewForm="TRUE"
			ShowInEditForm="TRUE" />
        <Field Type="Text"
			DisplayName="TextFieldWithVeryVeryLongInternalName"
			Required="FALSE"
			EnforceUniqueValues="FALSE"
			Indexed="FALSE"
			MaxLength="255"
			Group="Custom Columns"
			ID="{947d0169-b8c1-417b-aba9-891357b7d4d5}"
			SourceID="{d754b6da-6897-4a5a-8d73-49abb52cb20a}"
			StaticName="TextFieldWithVeryVeryLongInternalName"
			Name="TextFieldWithVeryVeryLongInterna"
			Version="1"
			Customization=""
			ColName="nvarchar16"
			RowOrdinal="0" />
    </Fields>
</ContentType>

Pay attention on TextFieldWithVeryVeryLongInternalName field. Title and StaticName are still set to original value (TextFieldWithVeryVeryLongInternalName) but InternalName is now trimmed to 32 symbols TextFieldWithVeryVeryLongInterna. Also notice that field ID is the same as in original site column:

{947d0169-b8c1-417b-aba9-891357b7d4d5}

In list field’s xml definition we will see the same:

<Field Type="Text"
       DisplayName="TextFieldWithVeryVeryLongInternalName"
	   Required="FALSE"
	   EnforceUniqueValues="FALSE"
	   Indexed="FALSE"
	   MaxLength="255"
	   Group="Custom Columns"
	   ID="{947d0169-b8c1-417b-aba9-891357b7d4d5}"
	   SourceID="{d754b6da-6897-4a5a-8d73-49abb52cb20a}"
	   StaticName="TextFieldWithVeryVeryLongInternalName"
	   Name="TextFieldWithVeryVeryLongInterna"
	   Version="1"
	   Customization=""
	   ColName="nvarchar16"
	   RowOrdinal="0" />

So this is the scenario when field’s InternalName and StaticName may be different: when you try to add site column which InternalName’s length is greater than 32 symbols to the list.

In addition to that I would also mention that if you would try to add more fields which have equal first 32 symbols in InternalName Sharepoint will add integer suffix to ensure that InternalName is still unique: TextFieldWithVeryVeryLongIntern0, TextFieldWithVeryVeryLongIntern1, etc.

Update 2021-09-27: also found that non-alphanumerical symbols are encoded in InternalName of list field. E.g. if we have site column with dash in it's name "Field-Test" then it's InternalName will be still "Field-Test" while InternalName of appropriate list field will be encoded "Field_x002d_Test1".