Can’t understand difference in fulltext results – contains, contains with wildcard, freetext

I have a table with an fulltext index on the column named Filecontent. The table has a row where content contains "W 917". For context, the content column on this rows contains much more than just what I’m searching for.

I don’t understand why I’m getting different results depending on whether I’m using contains, contains with wildcard or freetext. Why is CONTAINS without wildcard getting results, but CONTAINS with wildcard doesn’t?

-- Searching for "W 917" -- No match - CONTAINS with wildcard SELECT * FROM InvoicePDFContent t1 WHERE CONTAINS(t1.Filecontent, '"W 917*"')  -- Match - CONTAINS SELECT * FROM InvoicePDFContent t1 WHERE CONTAINS(t1.Filecontent, '"W 917"')  -- Match - FREETEXT SELECT * FROM InvoicePDFContent t1 WHERE FREETEXT(t1.Filecontent, '"W 917"')   -- Searching for "W" -- Match - CONTAINS with wildcard SELECT * FROM InvoicePDFContent t1 WHERE CONTAINS(t1.Filecontent, '"W*"')  -- No match - CONTAINS SELECT * FROM InvoicePDFContent t1 WHERE CONTAINS(t1.Filecontent, '"W"')  -- No match - FREETEXT SELECT * FROM InvoicePDFContent t1 WHERE FREETEXT(t1.Filecontent, '"W"') ยดยดยด 

Can I have a free-text comment tagged to a specific document that WON’T create a new version when edited?

I understand that if I have versioning enabled in my document library, then any changes I make to a document or its metadata will be represented in a new version of that document.

My customer has asked whether SharePoint can be made to support a free-form text field (or something) that can be tagged against a specific document. This would allow a user to type whatever (e.g. status, pending tasks, queries, etc), and it could appear – perhaps as a SharePoint column – against that document in the library view. If they edit this text, they do not want it to create a new version of the document, and they do not want ‘Approved’ documents suddenly going back to ‘Draft’.

I might need to think outside the box and push back on the client’s request slightly, but is there anything that is possible in this regard?

Thanks in advance!