While most contract drafting guides suggest we avoid legalese, they do usually see a point to what you could call “useful legalese”.
Take “hereby”, for instance. In her book Essential Contract Drafting Skills, Tiffany Kemp recongnises it as legalese:
Hereby is a word really encountered outside of contractual language. Frequently misspelled (‘herby’!), It is littered throughout contracts and legal documents with abandon, lending them a pleasantly (or unpleasantly, depending on your taste) legalistic flavour. p. 48
But she concedes that “it has a very useful role in documenting obligations are fulfilled immediately upon the execution of the contract.” p. 48 (Emphasis mine.)
So “hereby” is useful for signposting performance language, i.e., things coming into effect on the signing of the contract (e.g., the granting or transferring of something).
Do not, says Kemp, use it “simply to add ‘weight’ to other provisions such as warranties and representations.” p. 48
This makes sense. But I couldn’t see why guides like Kemp’s say not to use “hereby” with verbs like “warrant”. As these types of statements of fact (parties warranting, stating or acknowledging that something is the case) appear to happen at the time of signing, you’d think they warrant (sorry, couldn’t resist) the use of “hereby”.
Language of declaration vs performance
However, according to Kenneth Adams’s style manual, statements of fact are actually “language of declaration”, which apparently works in the same way as performance language (in the sense that it’s happening in the act) but doesn’t usually go with “hereby” because “hereby” doesn’t usually go with “verbs of speaking”. So there you go. Mystery solved.
Incidentally and in line with Kemp’s approach, apart from using “hereby” for performance language, Adams also suggests steering clear of all the other here- and there- adverbs, including the much loved “herein”. He says we should just say “in this agreement”.
The “useful” criterion for legalese
In any case, this kind of “useful legalese” approach is fairly typical of most contract drafting style guides. So with regard to legalese and other types of jargon and technical language, the idea seems to be: If it’s useful and adds something, use it; if it’s not, omit it.