Codification

Not compilation. A codification replaces what it draws on: after it, the earlier sources are no longer law, and the code is where the rule is found. That is what makes it expensive, politically difficult, and rare.

Attribution

Bentham's neologism, from around 1815. The Institutes and the wider Justinianic project are the most-cited instance of the practice in this collection, but they are an instance rather than the origin of the term, so they link in through about rather than through coined_in.

Why this is separate from legislative debt

Legislative debt is the condition; codification is one remedy. Holding them as one record would assert that every codification discharges the debt, which is precisely what for-the-love-of-law argues against: Justinian's code began accumulating its own layers almost immediately, and the Basilika and the Hexabiblos exist because of it.