What is the purpose of form layout "Available" red fields ?

[pawan_k_singh]

 For example if you open a user [sys_user] table and configure a "Form Layout", you will see this available fields which are coming in red color (Screenshot). This fields you can not find in "Form Design" or in the Table column of the user table. Please let me know why this section is there and use of it ?

[sachin_namjoshi]

Red fields means sys_user reference field are present on all these tables e.g Accessory, owner

Regards,

Sachin

[DrewW · Accepted solution]

Those are related lists that you can embed in the form rather than have them at the bottom as a tab.

 https://docs.servicenow.com/bundle/orlando-platform-user-interface/page/use/using-forms/concept/c_Em...

[Ujjwal Jain1]

I have created a custom table in another application and created a reference field of the global table on the custom application table.

I see in form layout the custom table --> Parent global table but not in Red colour is that fine ?