Reviewed 18 August 2026 · next review 17 February 2027
Controlled language checker with published rules
All 22 checks, their categories, severities and known false positives — nothing is hidden behind a score.
Last updated · Written and reviewed by Jonatan Tensetti · Tensetti Tools
Controlled language without a proprietary dictionary
A controlled language normally combines writing rules with an approved word list. ClearSpec implements the rule half openly and leaves the word list to you: your termbase defines preferred and banned terms, and the engine enforces the terms you chose. That keeps the tool useful in any domain and free of any claim about a specification it does not own.
ClearSpec uses an independent proprietary clarity method. It is not affiliated with ASD/STEMG, is not an ASD-STE100 checker or certification service, and does not certify ISO 24495-1 conformance.
The complete rule table
| Rule key | Detects | Category | Severity |
|---|---|---|---|
| CS_LONG_SENTENCE | The sentence is longer than the configured word threshold.False positive: A long enumerated list inside one sentence can be acceptable in a specification. | Sentence structure | medium |
| CS_MULTI_ACTION_STEP | One numbered or bulleted step contains more than one instruction verb.False positive: Two actions that must happen simultaneously may legitimately share a step. | Action clarity | medium |
| CS_PASSIVE_ACTION | An action is written in the passive voice, often with no visible actor.False positive: Passive voice is correct when the actor is genuinely irrelevant or unknown. | Action clarity | medium |
| CS_NOMINALISATION | A verb is buried in a noun after a weak verb such as perform or carry out.False positive: Some nominalisations are established terms of art in a specification. | Action clarity | low |
| CS_VAGUE_PRONOUN | A pronoun follows two or more candidate nouns, so its referent is ambiguous.False positive: The referent can be obvious from a diagram, caption or immediate context. | Action clarity | medium |
| CS_WEAK_MODAL | The requirement uses should, may or could rather than a definite obligation word.False positive: Genuinely optional advice should use a permissive word. | Action clarity | medium |
| CS_VAGUE_QUANTITY | An unmeasurable quantity, interval or quality word is used.False positive: An intentionally open tolerance may be defined elsewhere in the document set. | Sentence structure | medium |
| CS_DOUBLE_NEGATIVE | Two negative words appear in the same sentence.False positive: A quoted requirement may have to keep its original negative phrasing. | Sentence structure | high |
| CS_NESTED_CONDITION | One sentence contains two or more conditional markers.False positive: A short two-branch condition can be clear enough in a specification. | Sentence structure | medium |
| CS_NOUN_STACK | Four or more content words are stacked into one compound.False positive: An official part or assembly name may legitimately be a long cluster. | Sentence structure | medium |
| CS_TERM_VARIANT | The same term appears in more than one written form or capitalisation.False positive: A sentence-initial capital or a quoted label may be unavoidable. | Terminology | high |
| CS_UNDEFINED_ACRONYM | An acronym is used without an expansion earlier in the document.False positive: An acronym may be defined in a separate glossary or parent document. | Terminology | medium |
| CS_UNIT_VARIANT | The same unit is written with different spacing, case or spelling.False positive: A quoted value from a supplier document may keep its original form. | Consistency | high |
| CS_NUMBER_FORMAT | Decimal or thousands separators are mixed inside the same document.False positive: Mixed conventions can be intentional when quoting two external sources. | Consistency | medium |
| CS_WARNING_SEQUENCE | A warning, caution or danger statement does not clearly state the hazard, the consequence and how to avoid it.False positive: The missing part may appear in an adjacent block or a graphic. | Safety language | high |
| CS_MISSING_ACTOR | An obligation is stated without saying who must act.False positive: The responsible role can be fixed by the document scope. | Safety language | medium |
| CS_ADVERB_AMBIGUITY | A manner adverb such as carefully or properly describes the action.False positive: The adverb may reinforce a criterion that is stated elsewhere in the step. | Action clarity | low |
| CS_LONG_PARAGRAPH | A paragraph exceeds the length threshold for scannable technical text.False positive: Background sections can legitimately be longer than procedural text. | Sentence structure | low |
| CS_REPEATED_WORD | The same word appears twice in a row.False positive: Constructions such as 'had had' or a repeated identifier can be correct. | Consistency | low |
| CS_SLASH_COMPOUND | Two words are joined with a slash.False positive: Established pairs such as an on/off label may be intended. | Consistency | low |
| CS_FORBIDDEN_TERM | A term listed as banned in your termbase is used.False positive: A quotation of an external document may need the banned term. | Terminology | high |
| CS_PREFERRED_TERM_MISSING | A variant is used where your termbase defines a preferred term.False positive: The variant may be the correct term inside a quoted supplier name. | Terminology | medium |
22 rules implemented and covered by automated tests.
How the score is calculated
Each category starts at 100 and loses 10 points for a high finding, 5 for a medium and 2 for a low. Repeated identical findings are normalised: full weight once, then half, then a quarter, then nothing. The overall indicator is the weighted mean using Action clarity 25, Sentence structure 25, Terminology 20, Safety language 15, Consistency 15. Bands: 90+ clear, 75–89 focused editing, 50–74 material issues, below 50 substantial revision recommended.
The shared methodology page records how this method is versioned and how corrections are handled.
- CS_NOUN_STACK — 7 content words are stacked without a linking word. Insert prepositions, or split the cluster into a defined term plus a description.
- CS_DOUBLE_NEGATIVE — Two negatives ('not' and 'never') appear in one sentence. Rewrite it as a single positive statement of what must happen.
Possible false positive: An official part or assembly name may legitimately be a long cluster.
22 checks, no account, and the text is analysed in your browser.
Questions
- Why deterministic rules instead of AI?
- A deterministic rule can be published, argued with and reproduced. The same text, settings and method version always give the same result, which is what a review process needs.
- Can we switch a rule off?
- Paid tiers support approved exceptions, so a rule your house style deliberately breaks stops producing noise for your team.
- Is a low score a compliance failure?
- No. The indicator is an automated clarity heuristic. It is not a measure of technical accuracy, usability, legal sufficiency, safety or standards conformance.
References
Checked 18 August 2026. Referenced for context only; no standard text or dictionary content is reproduced.
- ISO 24495-1:2023 Plain language — Part 1 — ISO. Official standard information page. Context only; the standard is not reproduced or certified.
- Clear content objective — W3C WAI. Accessibility-oriented clear-content guidance informing general principles.
ClearSpec reports automated heuristics from method version 1.0.0. The clarity indicator is not a measure of technical accuracy, usability, legal sufficiency, safety or standards conformance. A competent person must decide the final wording, especially for safety content.