Communication skills glossary: plain against simple, brief against summary, approval against sign-off

Most of what gets sold as communication skill is advice about tone. The expensive failures are not about tone. They happen because two people used the same word for different things and neither noticed until the work was done.

So this is a glossary rather than a ranking: the words business writing runs on, defined tightly enough that you can tell them apart.

What to take away

Plain language

Plain language is writing arranged so that the intended reader can find what they need, understand it the first time, and act on it. Note the three parts. Something can be understandable and still be unfindable, and both can be true of a document nobody can act on.

It is not the same as simple language. Plain language keeps whatever technical terms the reader genuinely needs and defines them; simplification removes them and can remove the meaning with them.

It is also not the same as a readability score. A readability formula estimates difficulty from surface features: typically word length and sentence length. It does not read the document. A sentence can score well and still be ambiguous, and a necessary long word will be penalized for being long. Treat the score as a smoke alarm, not a verdict.

In some contexts plain language is not a preference. Certain public and financial disclosures are subject to specific drafting requirements, and where that is so, the applicable rule's own wording is the standard that binds, not any general writing guide. The regulator's plain writing materials are where to read what is actually required rather than what is generally recommended.

Documents that are not each other

Brief. Instructions issued before work starts: the objective, the

Summary. A condensed version of an existing document that preserves its proportions. If the original spent most of its length on one issue, so does the summary.

Abstract. A short, self-contained account of what a document contains and concludes, written so that a reader can decide whether to read the whole thing. Unlike a summary it is meant to stand alone.

Executive summary. A summary written to support a decision. It leads with the recommendation and the reason, and it is proportioned by what the decision needs, not by what the document contains. An executive summary that is just the first page of the report has been mislabeled.

Memo. A short internal document that records a position, a decision, or an analysis for a named audience. Its distinguishing feature is that it is meant to be referred back to.

Minutes. A record of what a meeting decided and who agreed to do what. Minutes are not a transcript, and the difference is deliberate: a transcript records everything said, minutes record what now binds.

Words about agreement

Approval. A named person with the authority to do so has said the thing may proceed. Approval implies authority.

Sign-off. Loose usage for approval, but it often means only that someone has seen the item. If the process depends on the difference, define which one you mean; "signed off" is not self-explaining.

Acknowledgment. Confirmation of receipt. It says nothing about agreement, and treating it as agreement is a recurring source of disputes.

Consensus. Everyone can live with the decision. It does not require that everyone prefers it.

Consent. Positive permission given by someone entitled to give it. In data protection and in medicine, consent is a defined legal concept with specific requirements that vary by jurisdiction, and the statutory definition governs regardless of how the word is used in a project meeting.

Words about time

Deadline. The point after which the work is late, with a consequence

attached. If nothing happens when it passes, it was a target date.

Target date. The date being aimed at, understood to be moveable.

Due date. The date an obligation falls due under an agreement. This one has contractual weight the other two do not.

As soon as possible. Not a date. It transfers the scheduling decision to the person who has the least information about your other commitments.

Voice, and the thing people misdiagnose

A sentence is in the passive voice when the grammatical subject is the one

being acted on, and the verb is a form of to be plus a past participle: the invoice was approved. It is active when the subject does the acting: the finance team approved the invoice.

Three things get called passive that are not. A sentence with was is not automatically passive: The meeting was long is a plain description. An impersonal sentence is not automatically passive: There are three options has no passive construction.

And a vague sentence is not passive, it is vague. Changes were made is passive and vague, and the vagueness hides who acted.

The passive is sometimes correct: when the actor is unknown, irrelevant, or deliberately not the point.

corporate jargon sets out three constructions that genuinely delete an actor, and only one is passive. Keep a narrower rule than "avoid the passive": do not use it to remove an actor the reader needs to identify.

Feedback, and its neighbors

Feedback is information about the effect of someone's work, given so it can be used. Its test is usefulness to the recipient.

Evaluation is a judgment against a standard. Its test is accuracy.

Appraisal is a formal, periodic evaluation attached to an employment process, often with consequences for pay or progression, and often governed by policy or by contract.

Coaching is help with how to do the thing, given over time.

Calling an appraisal "just some feedback" does not make it informal. Where a process is defined in an employment policy or contract, the defined process is the one that applies.

Where this goes wrong in practice

More of the vocabulary this depends on sits under communication skills, the speech acts that carry an ask are sorted in the asking and chasing words, and the structural versions of these faults are listed among the nine communication errors.

Common questions

Is plain language the same as writing short?

No, and treating it that way produces documents that are quick to read and impossible to act on. Clear and short are separate targets, and federal guidance on writing for understanding treats findability and usability as part of the same job.

Should I define terms in an ordinary email?

Only the one the message turns on, and only where you have reason to think the reader uses it differently. One clause in parentheses is usually enough.

What do I do about a word my organization uses wrongly?

Use it, and add the precise version alongside where the difference matters. Correcting the usage is a separate project from getting this message acted on, and mixing the two loses both.

How do I tell whether a document is clear enough?

Give it to one person who has to act on it and watch what they do. That is worth more than any amount of rereading it yourself, and it is the only check that tests the reader rather than the writer.