Independent reference · Avellio-aware QA

Typography Rules & Common Typesetting Errors

A practical reference to typography rules, common typesetting errors, language-specific conventions, and how to detect them in Adobe InDesign.

18 complete rules12 locale guides34 Avellio profiles
Four discovery paths

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Categories

From characters to composition.

Knowledge base

All rules and locale guides.

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CompositionStrong composition convention

Widows & Orphans

A widow or orphan is an isolated line of a paragraph separated from the lines it belongs with at the top or bottom of a column or page.

WIDOWORPHAN
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CompositionConfigurable composition heuristic

Short Last Lines

A short last line is a paragraph ending whose occupied width is small enough to look weak, ambiguous, or visually detached.

SHORT_LINE
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CompositionVisual composition heuristic

Rivers of White Space

A river is a conspicuous vertical or diagonal path formed by aligned word spaces across neighboring lines.

RIVER
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MicrotypographyStrong prose convention

Double Spaces

A double space is a run of two or more ordinary word spaces where contemporary typeset prose expects one.

DOUBLE_SPACE
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MicrotypographyEditorial heuristic

Repeated Words

A repeated-word finding identifies adjacent identical words that may be an accidental duplication.

REPEATED_WORD
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MicrotypographyLocale and house-style dependent

Straight vs Typographic Quotes

Straight ASCII quote marks are generic keyboard characters; typographic quotation marks and apostrophes have opening, closing, and locale-dependent forms.

STRAIGHT_QUOTESMART_QUOTE
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MicrotypographyLocale and house-style dependent

Quotation Marks by Language

Quotation mark shape, direction, nesting, spacing, and punctuation placement depend on language, region, and editorial style.

SMART_QUOTESTRAIGHT_QUOTE
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MicrotypographyLocale-dependent convention

Punctuation Spacing

Punctuation spacing controls whether a space is required, forbidden, or non-breaking before and after a punctuation mark.

PUNC_SPACE_BEFOREPUNC_SPACE_AFTERREPEATED_PUNCT
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Breaks & StructureStrong structural principle with locale-specific applications

Non-breaking Spaces

A non-breaking space preserves visible separation while preventing a line break between related items.

PREPOSITIONUNIT_SPACE
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MicrotypographyFunction-based, with house-style choices

Hyphen, En Dash & Em Dash

Hyphens join or divide words; en and em dashes express ranges, relationships, interruptions, or parenthetical structure according to editorial style.

DASH_USAGE
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MicrotypographyStrong character distinction; spacing is style-dependent

Ellipsis

An ellipsis represents omitted or trailing content; its character form and surrounding spaces must follow the publication’s language and style.

ELLIPSIS
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CompositionConfigurable composition convention

Hyphenation Ladders

A hyphenation ladder is a run of consecutive lines ending in hyphens beyond the publication’s tolerated limit.

HYPHENATION
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CompositionVisual composition heuristic

Bad Rag

Rag describes the changing edge of unjustified text; a bad rag contains distracting shapes, abrupt steps, or accidental patterns.

BAD_RAG
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CompositionDesign-system convention

Vertical Rhythm

Vertical rhythm is the repeated spacing pattern created by leading, paragraph spacing, baselines, and aligned text structures across a layout.

RHYTHMVERTICAL_RHYTHM
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Semantic TypographyStrong semantic convention with locale exceptions

Number & Unit Spacing

A number and its measurement unit normally form one semantic pair and should use the locale’s expected spacing without breaking across lines.

UNIT_SPACE
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Semantic TypographyLocale-dependent convention

Date Formats

Date order, separators, month names, and abbreviations are locale- and purpose-dependent; ambiguous numeric dates require human interpretation.

DATE_FORMAT
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Semantic TypographyLocale-dependent semantic convention

Number Separators

Decimal and grouping separators are locale-dependent symbols whose incorrect substitution can change numerical meaning.

NUM_FORMAT
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Semantic TypographyLocale and accounting-style dependent

Currency Typography

Currency typography combines symbol or code, value, placement, spacing, and locale or accounting convention.

CURRENCY_LOGIC
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Language / locale5 profiles

English Typography Rules

English conventions vary substantially by region and publisher, especially quotation hierarchy, dash style, date order, and currency context.

EN IntlEN USEN UKEN AUEN NZ
Open locale guide
Language / locale3 profiles

German Typography Rules

German, Austrian, and Swiss German publishing share a language family but differ in quotation practice, currency context, grouping, and the use of ß.

DEDE ATDE CH
Open locale guide
Language / locale3 profiles

French Typography Rules

French typography is especially sensitive to guillemet spacing and high-punctuation spacing, with meaningful differences among France, Switzerland, and Canada.

FRFR CHFR CA
Open locale guide
Language / locale6 profiles

Spanish Typography Rules

Spanish publishing combines paired inverted punctuation with regional differences in separators and currency, especially across Latin America.

ESES LatAmES ARES CLES COES PE
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Language / locale2 profiles

Portuguese Typography Rules

European Portuguese and Brazilian Portuguese differ in quotation preference and currency while sharing day-first dates and decimal-comma conventions.

PTBR
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Language / locale2 profiles

Italian Typography Rules

Italian and Swiss Italian profiles differ mainly in Swiss number and currency conventions while retaining Italian language behavior.

ITIT CH
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Language / locale4 profiles

Nordic Typography Profiles

Swedish, Danish, Norwegian, and Finnish are separate conservative Avellio profiles collected here for comparison without pretending they share one language standard.

SEDANOFI
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