I don't collect the PO coded chips as they are what I call die cuts, not crest and seals.

Recently I bought these two chips on eBay. One is T/T. The other is W/C. These are inlaid chips.

Are they common? I don't recall seeing such chips. Are they coded?

Even though the W/C chip is a custom order (probably the T/T also), I guess they go in the Generics section.