Word usage

Choose the word that preserves the technical distinction. Use the glossary for product concepts and interface actions for commands and gestures. An existing label or identifier keeps its exact spelling, even when new prose would use another form.

Obligation, possibility, and conditions

Words	Distinction
must, should, can	A requirement, a recommendation, and a capability or permission. State which meaning of can applies if it could be misunderstood.
might, can	A possible outcome is not the same as an available capability. “The export might fail” expresses uncertainty; “You can export a PDF” states an available action.
if, when, whether	Use if for a condition, when for an expected occasion or timing, and whether for alternatives. Do not imply that an optional event will happen.
ensure, assure, insure	Make something certain, reassure someone, and provide insurance. Do not write ensure when the action only reduces a risk.
fewer, less	Use fewer for countable items and less for an amount: fewer glyphs, less storage space.
earlier, later	Give the boundary version and say whether it is included. “Version 3 and later” includes version 3; “after version 3” does not.

For recommendations and prerequisites, see task guidance.

Software state and lifecycle

Words	Distinction
deprecated, removed, unsupported	Discouraged for continued use, no longer present, and outside the stated support scope. These states can overlap but are not interchangeable. Give the verified replacement and relevant version.
update, upgrade	Follow the product's actual release and purchasing terms. Neither word alone establishes price, compatibility, or entitlement.
beta, preview	Preserve the release's stated designation. Do not rename one as the other to improve its tone.
failed, unresponsive, exited unexpectedly	An operation did not succeed, a program stopped responding, or a process ended unexpectedly. Describe the observed state and any known effect on output.
unavailable, off, unselected	An action cannot currently be used, a setting is off, or an item is outside the selection. Explain the relevant state without relying on its color.

See interface feedback for errors and recovery.

Data and developer terms

Words	Distinction
parameter, argument	A parameter belongs to a function's definition; an argument is supplied in a call. A product control called a parameter retains its product meaning.
null, empty, zero	Absence represented by a null value, a present value with no contents, and a numeric value. State the API or format's actual treatment of each.
home, root, current directory	The user's home directory, the root of the named filesystem or project, and the working directory. Identify which root you mean.
file, document	A document is a kind of file in the relevant workflow. Do not assume that every file can be edited or printed.
folder, directory	Use folder for ordinary file organization and directory where filesystem or developer terminology matters. Preserve named controls and APIs.
display name, identifier	A name shown to people and a value used to identify an object. Renaming one does not necessarily change the other.
plain text, plaintext	Text without rich formatting, and unencrypted information in a security context. Plain text can use Unicode; name the encoding when it matters.
memory, storage	Working memory and retained data storage. Name the resource that limits the operation rather than asking for “more space” without context.
bit, byte	Different units of information. Preserve unit symbols and distinguish a data quantity from a transfer rate.
account, credential	An account is not the password, passkey, or verification code used to authenticate. Ask for the particular input the product requires.

Use technical notation for literal paths, URLs, units, and symbols. Use developer examples for parameter descriptions and executable input.

Typography and interface terms

A character, code point, and glyph are related but different concepts. A glyph can represent several characters, and a character can have several glyph forms. An icon describes a visual role in an interface; it is not a replacement term for every glyph or symbol. See scripts and typography and the type-design glossary.

Keep font, typeface, family, style, weight, and slant distinct when the task needs those distinctions. Do not replace typeface with font throughout specialist writing. Regular, roman, and italic are not universal synonyms for “normal” and “formatted.” Use the verified style name when identifying a font.

A baseline in type design is not a benchmark. A geometric axis or design-space axis is not necessarily a chart's category axis. Define the quantity or role in context.

A pointer indicates a pointing location; an insertion point shows where entered text will appear. A heading names a section; a header is a region such as the top of a page or a field in a protocol. A page is part of a site. Prefer the specific object when a general word could send the reader to the wrong place.

Written forms

Form	Example or scope
back up; backup	Back up the folder. Keep the backup.
set up; setup	Set up the project. Review the setup.
lay out; layout	Lay out the page. Check the layout.
sign in; sign-in	Sign in to your account. Follow the sign-in instructions. Preserve a named authentication feature or literal command.
read-only	A read-only file.
real time; real-time	Preview changes in real time. Use a real-time preview.
filename; file extension	The filename is Example.otf; its extension is .otf.
email; website; webpage	House forms in ordinary English prose. Preserve quoted labels and proper names.

Do not maintain a long replacement list for ordinary words. Edit an unclear actor, ambiguous condition, or unnecessary abstraction in its sentence. A synonym that changes the action, data, or promise is not a style correction.