Currently, when an specification is created, it's set as either a SKU or Product type and this should not be changed after its creation.

However, there a glitch in the catalog admin that allows these fields to be incorrectly changed from their original type (from SKU to product or vice-versa), when manipulating the URL of the admin page.

1 - access a product specification list in your account https://account_name.myvtex.com/admin/site/Campo.aspx

2 - create a specification and hit save

3 - its format will have the following query parameters (example) ...CampoForm.aspx?Id=20&flagSku=0&idCategoria=3 --> the "flagSKu" data = 0 means it is a product specification.

4 - change this flag to =1 and hit enter.

5 - Upon reloading the page, hit save.

6 - the product specification was now converted to a product specification, which is not a desired behaviour in the catalog.