What is the background page while creating a new SharePoint List

Question

When I create a SharePoint list, the page doesn't shows the right side bar. However, creating a new SharePoint page reflects the right side bar.

Therefore would like to confirm as which background page does SharePoint uses while creating the List page.

Currently, all my List & Document Library page don't have the right side bar.

Answer 1

It seems you have used different master page for System master page and site master page.That is why it is coming different for both of them.

Answer 2

Below given URL of that page from where the list is going to be created.

http://serverURL/_layouts/15/new.aspx?FeatureId=%7B00bfea71%2Dde22%2D43b2%2Da848%2Dc05709900100%7D&ListTemplate=100&IsDlg=1

The number 100 for ListTemplate represents the type of the list you are creating. here given URL is used to create a custom list.

If you want to create a library than you can replace the number in ListTemplate parameter in the given URL.

You can remove &IsDlg=1 from the parameter to see the page within your SharePoint Master page as a normal page.