Should I choose to extend the OOTB table or create a custom table? What is the point of view to choi

[KazukiM]

I want a table that manages the skill ownership status of each user.

1. Extend the user table. (adding columns that represent each skill.)
2. Prepare an independent custom table. (with a reference to the user table and columns that represent each skill.)
3. Or, an OOTB table that represents the skill ownership status is already present.

Which is correct?

Also, if No.3 is not possible, in what point of view should I choose between No.1 and 2?

I think I should choose extension in these cases, but is this correct?

・Use the business rules of the extension source.
・Create a record in the extension source.
・Need to download a file.

[Dr Atul G- LNG]

Hi @KazukiM 

Extension should be first recommendation, the reason begin you get inherited all scripts/ UI logics and parent table field as well to  use.