The disagreements are between authorities, not between right and wrong

Take numbers. The Government Publishing Office requires a figure for a single number of 10 or more, with 50 ballots and 24 horses among its examples.2 Chicago's general rule spells out the whole numbers zero through one hundred and extends that to multiples of a hundred.3 Both are American, both are current, and a manuscript can follow only one.

Take the serial comma. The GPO requires a comma after each member within a series of three or more words, phrases, letters, or figures used with and, or, or nor.4 Other American drafting conventions omit it. A checker that flags one of those practices is not detecting an error. It is enforcing a preference that a publisher may not share.

A checker cannot resolve that, because it does not know where the document is going. A publisher does, and it has usually said so in writing.

What a checker is genuinely good at

Three categories are worth keeping switched on, and they share a property. None of them requires the software to know where the document is going.

The first is mechanical slips that no authority disputes. A doubled word, an unclosed quotation mark, a subject and verb that disagree in number, and a sentence with no finite verb are errors under every manual.

The second is consistency prompts within one document, where the software notices that a compound is hyphenated in one place and open in another. It cannot tell which is right. It can tell that they differ, which is the useful half.

The third is reading-level and sentence-length reports, which are measurements rather than judgments. A mean sentence length is a number, and a number is something an author can act on.

What it cannot see, and why the gap matters

A checker tests whether a string is a word and whether a construction matches a pattern. It cannot test whether the word is the right word.

Real words in the wrong place pass every dictionary: form for from, casual for causal, trial for trail. Numbers pass entirely, because nothing in the software knows which figure was intended. Names spelled two ways in one paragraph pass unless the software happens to have learned one of them. And an ambiguous sentence, the fault most likely to cost a reader, is grammatically perfect by definition.

That is the same gap that separates the two kinds of check on any document. One asks whether the text conforms to a pattern. The other asks whether it says what its author meant.

The setting worth changing

Because the settings apply to every document rather than to one, an author working across several destinations is applying one publisher's conventions to all of them.1 The practical response is to switch off the rules the destination does not share, and to record the destination's own conventions somewhere the software cannot overwrite.

That record has a name. Editors Canada includes the development of style sheets within copy editing, alongside checking mechanical consistency.5 A style sheet survives a change of software, a change of editor, and a change of manuscript.

What a person adds

An editor working on a manuscript applies the authority the document has chosen, records every decision that authority did not settle, and reports what reads two ways. None of that is available from a checker, and all of it is available before a publisher sees the manuscript.

EditFast works to whichever style authority a client names, returns the style sheet with the manuscript, and does not impose a house style on work that already has one. Everything a client sends is treated in confidence, including drafts, manuscripts under submission, and correspondence.

An author who has been arguing with their software for a year usually finds the argument ends the moment the destination is named. The software was never the authority. It was standing in for one that had not been chosen yet, and choosing one takes an afternoon.