Creating a listing some fields are there when you hit on someone else's listing "sell now" while

[mirror-in-the-attic]

if you do a listing of your own, from nil, those fields are non existent.

For example,  clothing:   I remember there used to  be a "sell similar" field or does my memory fail me?

The fields are identifiers like hem to waist length, type of neckline, etc.  the basic identifiers are in the blank  template but not those and I see no way to incorporate them into it. (like a drop down arrow)

1. Not sure if I am making sense.  

[fern*wood]

I can't vouch for every category, but all the ones that I use have a spot to enter your own item specifics among some pre-printed ones.  Measurements sounds like something that particular seller entered themselves. 

[fashunu4eeuh]

I use the Advanced Listing Tool and the Item Specifics are always available in that form. Given how important they are said to be, they are available in all listing formats. Normally there is a blue button to click on that says Write Your Own and then you add whatever identifiers you wish.  Some categories provide more IS choices than others and have some boxes filled in already.

There is a Sell Similar choice in listing/relisting and it often has some Item Specifics already pre-populated in the IS section of the Sell Your Item form.

I hope this info addresses your query.