Deprecated not depreciated

I've seen a number of modules marked as depreciated, rather than deprecated.

deprecate: To mark (a component of a software standard) as obsolete to warn against its use in the future so that it may be phased out.
  1. To lessen the price or value of.
  2. To write off an expenditure for (a tangible asset) by prorating over a certain period, usually the estimated useful life of the asset.

I'm guessing that people aren't using their CPAN work to help balance their books...

Definitions from


Thanks for pointing this out. I'm surprised at how many modules get it wrong. At least it's small compared to the amount that get it right. I was disappointed to see that even Finance::Quote uses depreciated incorrectly!

Glad to see I'm not the only one who noticed the typo in Finance::Quote. :)

Deprecate vs Depreciate - why I am right, and the rest of the computer industry is emphatically and consistently wrong. :)

A blog or what you will...

Since I was 4, my Grandmother used to play Scrabble with me. This is back when Scrabble had more respect for the English language, e.g., proper names were not allowed, nor were words from other languages not commonly used in English, etc. Every time she played a word she would ask me if I knew what it meant, and if I didn't, she made me look it up in this huge Oxford dictionary she had. Thing was like the Gutenberg bible. I'm talking huge. You can imagine that when I started playing Scrabble with her this occurred quite frequently. At the time I was mostly annoyed, but now, I look back on her with enormous gratitude for instilling in me a decent vocabulary. Unfortunately, she also instilled in me a rather stuck-up prudish attitude towards incorrect use of the English language. Hey, I still make mistakes, but as soon as someone points it out to me or I realize what I've done, I course correct. I don't keep repeating the same mistake because it suits me.

Granted language evolves, e.g., "google" is now a verb, apparently. Through what's known as "common use", it has earned its way into official dictionaries. However, "google" was a new word representing something heretofore non-existent in our speech.

Common use does not cover blatantly changing the meaning of a word just because we didn't understand its definition in the first place, no matter how many people keep repeating it.

The entire English-speaking computer industry seems to use "deprecate" to mean some feature that is being phased out or no longer relevant. Not bad, just not recommended. Usually, because there is a new and better replacement.

The actual definition of deprecate is to put down, or speak negatively about, or to express disapproval, or make fun of someone or something through degradation.

It comes from Latin de- (against) precari (to pray). To "pray against" to a 21st century person probably conjures up thoughts of warding off evil spirits or something, which is probably where the disconnect occurs with people. In fact, to pray or to pray for something meant to wish good upon, to speak about in a positive way. To pray against would be to speak ill of or to put down or denigrate. See this excerpt from the Oxford English Dictionary.

1. Express disapproval of:
(as adjective deprecating) he sniffed in a deprecating way

2. another term for depreciate ( sense 2).
he deprecates the value of children’s television

What people generally mean to convey when using deprecate, in the IT industry anyway, and perhaps others, is that something has lost value. Something has lost relevance. Something has fallen out of favor. Not that it has no value, it is just not as valuable as before (probably due to being replaced by something new.) We do have a word that means this in English and the word is "depreciate". See this excerpt from the Oxford English Dictionary.

1. Diminish in value over a period of time:
the pound is expected to depreciate against the dollar

2. Disparage or belittle (something):

Notice that definition 2 sounds like deprecate. So, ironically, deprecate can mean depreciate in some contexts, just not the one commonly used by IT folk.

Also, just because currency depreciation is a nice common use of the word depreciate, and therefore easy to cite as an example, doesn't mean it's the only context in which the word is relevant. It's just an example. ONE example.

It bugs me, it just bugs me. I don't know why. Maybe because I see it everywhere. In every computer book I read, every lecture I attend, and on every technical site on the internet, someone invariably drops the d-bomb sooner or later. If this one ends up in the dictionary at some point, I will concede, but conclude that the gatekeepers of the English lexicon have become weak and have lost their way... or at the very least, lost their nerve. Even Wikipedia espouses this misuse, and indeed, defends it. I've already edited the page thrice, and they keep removing my edits. :D

Something is depreciated until it is obsolete. It is actually deprecate, in the context of IT, that makes no sense at all.

That's it. I'm done, and while I'm sure there are grammatical mistakes in this soliloquy and a spelling error or two due to auto-correct or the fact that I don't type and have to look at the keys the whole time, my argument stands.

Still, most people in my industry don't care. As someone remarked to me at the Openstack convention in Atlanta when I gave him this same speech, "Irregardless, I'm still going to keep saying deprecated."


First of all, pay attention to the usage examples in the very definition you quoted:

  • he deprecates the value of children’s television”
  • the pound is expected to depreciate against the dollar”

“To depreciate” is intransitive; “to deprecate” is transitive. Depreciating is something a thing of value does, by itself; deprecating is stance someone takes towards something.

The contested usage is saying that “module X is depreciated”. By the given dictionary definitions this is clearly incorrect, no matter whether you think the error is in the chosen word or the chosen transitivity. Either the module has depreciated (by itself) or it is deprecated by its author (or the community), but the neither-fish-nor-fowl usage is unequivocally wrong.

And it’s obviously the latter: the module is being deprecated by its author (or the community), i.e. the author (or community) now considers it a bad idea to use it. Loss of value doesn’t even make sense here: module X has depreciated? How? The price for modules on CPAN has dropped so now the thing sells for less? This is clearly about an expression of disapproval, not diminishment in exchange value (of which it never had any).

The transitivity of depreciated is irrelevant and not a valid defense of the use of deprecate in the context of software. You can most certainly say a module _has_ depreciated. This would indeed imply that it is not recommended. It makes perfect sense. When something has depreciated, it has lost value. The official OED definition of this word in no way prohibits its use to finance, nor is the only context in which it is used. Citing examples of this context does not further your case.

The correct transitive verb to use here is obsolete. Again, see the OED definition. Wikipedia and other online "community" sources are un-reliable because they can be based on hear-say and mis-information.

obsolete - v. (transitive) - Cause (a product or idea) to be or become obsolete by replacing it with something new:
we’re trying to stimulate the business by obsoleting last year’s designs

Depreciated and obsolete makes sense, deprecate does not. I'm not making this up and you can choose to accept the truth or not, but according to the official lexicon of the English language, I am right on this.

To deprecate means strictly to demean or to denigrate. It does NOT mean to just recommend against.

The author doesn't demean a module, does she? Does a module become ridiculed? No. This is ridiculous. It's just not correct and it never has been.

See reply below

EDIT: Meant to say "prohibits its use to ONLY finance" in paragraph one.

@Jason you are my legend, I created an account to post this! The articles claiming deprecated was the correct use for Software nearly had me doubting myself!! Thanks for the clear breakdown and analysis, you legend!

Great. So now that's sorted perhaps we can move on to letting people know that "performant" isn't a word.

OK, yes, it is, but it doesn't mean what you think it means.

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About Neil Bowers

user-pic Perl hacker since 1992.