Douglas King

And just like with code, in a small codebase [doc set] with only a few developers [writers] on it, a conditional here & there is fine. But when you've got hundreds of developers [writers]...it stops working quick.

Any existing conditional will attract more conditionals, because humans are nothing if not pattern followers. And when you come into the file, it sure looks like the thing to do is reuse the fragment but add your exception/special handling to the list!

I'm sure there's a law already out there about conditionals attracting more conditionals. If not, it's now Mei's First Law

In a codebase that evolves over time, the trick to keeping it nimble is to constantly be re-evaluating, for every piece of the code you look at, whether the see-saw of reuse<--->duplication is leaning at exactly the right angle.

Turns out it's the same in a big doc set. And every now and then, it turns out, the folks who own these large doc sets need to re-evaluate what they call their "reuse strategy."

Otherwise, you end up with a big ball of mud for a docset, so fragile that you can't even really tell what the consequences of even a small change will be. This drastically reduces the speed with which _any_ docs can be produced.