SharePoint: ContentTypeID Query String Parameter in List Item Url

Hello Again,

This is again very basic blog but just writing; since I get confused between site and list content types and then spent some time on to get things clear.

In one of our project task, we were working on list items. When I saw list item URL it contains the one of the query string parameter ContentTypeID.

For ex. I added some items in Tasks list and checked the properties it shows the URL of list item as follows:

<Site Url>/_layouts/listform.aspx?PageType=4&ListId={EC506158-BA24-4283-B931-ADCB6855F325}&ID=1&ContentTypeID=0x01080098850864CC156845BDB2687D80484128

I was wondering for the ContentTypeID query string parameter that how this Id formed. From ContentTypeID value it understood that 0x0108 is id of Task of content type id but then confused for 98850864CC156845BDB2687D80484128 id.

But after doing some research it found that this is ID for the list content type Task. So basically there are two types of content types :

1. Site Content Type.
2. List Content Type.

So whenever we associate any content type to list it becomes a list content type. SharePoint makes the copy of original site content type with new id and associate with list. This new content type id is derived from the original site content type id.

Reference: Site and List Content Types.

Suggestions / Comments always welcome.

Enjoy reading
Thanks!