I have designed a custom master page in Sharepoint online if I select my custom master page in system master page section(Site Settings->Site Master Page Settings->Specify a system master page), the master page will be applied to all the SharePoint inbuilt pages. But I want to apply custom master page only to VersionDiff.aspx. Is there any way that, I can apply custom master page only for VersionDiff.aspx in SharePoint online. I want to write some custom coding on this page. Can anyone please help me on this?