--- name: latex-typography-conventions source: https://app.decimal.ai/s/latex-typography-conventions@1/SKILL.md source_sha256: 15e13080c2c9 --- # LaTeX Typography Conventions ## Contract When you emit LaTeX source for an academic manuscript, produce it in the cross-venue typographic conventions below. Apply this any time you write or fix `.tex` content — tables, figures, prose, math, references, units. These are exact, arbitrary TeX-specific forms; the naive default (straight quotes, `\hline`, `10-20`, `...`, `$$`) is what an inexperienced author types and what reviewers read as amateur typesetting. ## Rules ### R1 — Table rules use booktabs - Use the `booktabs` rules `\toprule` (top), `\midrule` (under the header), `\bottomrule` (bottom). Never `\hline`. - Never emit a double horizontal rule (`\hline\hline`, or `\toprule\toprule`). - One `\midrule` separates the header row from the body; do not rule between every data row. ### R2 — No vertical rules in the column spec - The `tabular`/`array` column spec carries letters only: `{lcr}`, `{llc}`. - Never put a vertical bar `|` in the spec (`{|l|c|r|}`). Vertical rules in a table are the single clearest amateur tell. - Numeric columns are right-aligned (`r`) or decimal-aligned (`S` from `siunitx`); text columns are left-aligned (`l`). ### R3 — Table caption goes ABOVE the table - Emit `\caption{}` BEFORE `\begin{tabular}`, inside the `table` float. - A table caption below the tabular is wrong — below is for figures (R4). ### R4 — Figure caption goes BELOW the figure - Emit `\caption{}` AFTER `\includegraphics`, inside the `figure` float. - A figure caption above the graphic is wrong — above is for tables (R3). ### R5 — Float placement is `[htbp]` - Use `[htbp]` (or `[tbp]`, `[t]`) on `\begin{table}` / `\begin{figure}`. - Never `[H]` (forces placement, creates large whitespace gaps) and never `[h!]`. Plain `[h]` alone is fragile — avoid it too. ### R6 — Ranges use an en-dash `--` - Number, page, and year ranges use a double hyphen (en-dash): `10--20`, `pp.\ 5--12`, `2020--2023`. Never a single hyphen `10-20` for a range. ### R7 — Em-dash `---` for asides, hyphen for compounds - A parenthetical aside or emphatic break uses an em-dash, three hyphens: `text---text`. Apply spacing uniformly (closed `text---text` is the academic default). - A single hyphen `-` is only for compound words (`state-of-the-art`, `well-known`). Never use a single hyphen where a range (R6) or aside belongs. ### R8 — Quotes are TeX quotes - Open a quotation with two backticks `` `` `` and close with two apostrophes `''`. Never the straight `"` keyboard character — it renders as two wrong glyphs in TeX. - Nested: single backtick / single apostrophe inside the doubles: `` ``He called it `optimal' which is debatable.'' `` ### R9 — Ellipsis is `\ldots` - An ellipsis is `\ldots` (or `\dots`). Never three literal periods `...`, which TeX sets with wrong inter-dot spacing. ### R10 — Non-breaking tilde before refs and cites - Put a non-breaking tilde `~` immediately before every cross-reference and citation: `Figure~\ref{fig:x}`, `Table~\ref{tab:x}`, `Section~\ref{sec:x}`, `Equation~\eqref{eq:x}`, and `prior work~\cite{smith2020}`. - The tilde prevents a line break that would strand the label ("Figure") at the end of one line and the number on the next. ### R11 — Thin space between a number and its unit - Join a number and its unit with a thin space `\,`: `10\,ms`, `8\,GB`, `100\,K`. Equivalently use `siunitx`: `\SI{10}{\milli\second}` / `\qty{10}{ms}`. - Never `10ms` (no space) and never `10 ms` (a plain inter-word space, which TeX may break across lines). ### R12 — Inline fractions use `\nicefrac` - In running prose write an inline fraction as `\nicefrac{1}{2}` (or `\sfrac{1}{2}` from `xfrac`). Never an inline `$\frac{1}{2}$`, which creates a tall element that disrupts line spacing. - `\frac` is correct only inside display math (R13). ### R13 — Display math uses `\[ ... \]` - Display an equation with `\[ ... \]` or an `equation`/`align` environment. - Never `$$ ... $$` — that is plain TeX, not LaTeX, and produces incorrect vertical spacing. ### R14 — Multiplication and degree symbols - Multiplication is `$\times$` (e.g. a `$3 \times 3$` kernel). Never the letter `x`. - A degree symbol is `$^\circ$` or `\textdegree` (or a `siunitx` celsius command). Never the Unicode `°` character. ### R15 — Emphasis is `\emph{}` - Emphasize a word with `\emph{...}`. Never `\textbf`, `\textit`, ALL CAPS, or a color command for stress in running prose — `\emph` is semantic and nests correctly. ### R16 — Escape reserved characters in text - Escape `\&`, `\%`, `\#`, `\_` whenever they appear as literal text. A bare `&`, `%`, `#`, or `_` is a TeX control character and breaks compilation or is silently dropped. ### R17 — URLs go in `\url{}` - Wrap a URL in `\url{...}` or `\href{...}{...}`. Never leave it as bare text and never put it in `\texttt{...}` — only `\url` allows the line breaks that prevent an overfull margin. ## Worked examples (BEFORE = the naive default, AFTER = conforming) R1/R2/R3 — table: ```latex % BEFORE \begin{table}[H] \begin{tabular}{|l|c|r|} \hline Method & Accuracy & F1 \\ \hline\hline Ours & 0.94 & 0.91 \\ \hline \end{tabular} \caption{Results.} \end{table} % AFTER \begin{table}[htbp] \caption{Results.} \begin{tabular}{lcr} \toprule Method & Accuracy & F1 \\ \midrule Ours & 0.94 & 0.91 \\ \bottomrule \end{tabular} \end{table} ``` R4/R5 — figure: ```latex % BEFORE \begin{figure}[H] \caption{Training curves over 100 epochs} \includegraphics{results.png} \end{figure} % AFTER \begin{figure}[htbp] \includegraphics{results.png} \caption{Training curves over 100 epochs} \end{figure} ``` R6 — number range: BEFORE `See pages 10-20.` → AFTER `See pages 10--20.` R6 — year range: BEFORE `the years 2020-2023` → AFTER `the years 2020--2023` R7 — aside: BEFORE `works well, in fact better than expected, on all` → AFTER `works well---in fact better than expected---on all` R8 — quotes: BEFORE `the result was "surprising"` → AFTER ``the result was ``surprising'' `` R8 — nested: BEFORE `She said "He called it 'optimal'."` → AFTER ``She said ``He called it `optimal'.'' `` R9 — ellipsis: BEFORE `the analysis trailed off...` → AFTER `the analysis trailed off\ldots` R10 — ref: BEFORE `As shown in Figure \ref{fig:curve}` → AFTER `As shown in Figure~\ref{fig:curve}` R10 — cite: BEFORE `Prior work \cite{smith2020}` → AFTER `Prior work~\cite{smith2020}` R11 — unit: BEFORE `latency was 10 ms` or `10ms` → AFTER `latency was 10\,ms` R11 — unit: BEFORE `under 8 GB` → AFTER `under 8\,GB` R12 — fraction: BEFORE `about $\frac{1}{2}$ of the runs` → AFTER `about \nicefrac{1}{2} of the runs` R13 — display math: BEFORE `$$L = \sum_i (y_i - \hat{y}_i)^2$$` → AFTER `\[ L = \sum_i (y_i - \hat{y}_i)^2 \]` R14 — multiply: BEFORE `a 3 x 3 convolution` → AFTER `a $3 \times 3$ convolution` R14 — degree: BEFORE `at 25°C` → AFTER `at $25^\circ$C` R15 — emphasis: BEFORE `This step is \textbf{critical}.` → AFTER `This step is \emph{critical}.` R16 — escapes: BEFORE `Smith & Jones, a 5% gain` → AFTER `Smith \& Jones, a 5\% gain` R16 — underscore: BEFORE `the field max_value` → AFTER `the field max\_value` R17 — URL: BEFORE `available at https://example.com/repo/path` → AFTER `available at \url{https://example.com/repo/path}` ## Edge cases & exceptions - **Hyphen vs en-dash vs em-dash.** Three distinct marks: hyphen `-` joins a compound word, en-dash `--` spans a range, em-dash `---` breaks a clause. When in doubt about a numeric "A to B," it is a range → `--`. - **Document class owns the table style.** If the class mandates a table style (e.g. `IEEEtran`), follow it rather than imposing booktabs — but the default case is always booktabs. - **Percent and degree spacing.** `%` after a number conventionally touches it (`14.3\%`); a unit like `ms`/`GB` does not (`10\,ms`). Either way `%` is still escaped as `\%`. - **`\frac` is right in display math.** R12 forbids inline `$\frac{}{}$`, not `\frac` itself — inside `\[ ... \]` or `equation`, `\frac` is correct. - **Naturalized Latin.** `et al.`, `vs.`, `e.g.`, `i.e.` are set upright (not italic) and take a period; this is orthogonal to R15 emphasis. - **Minus vs hyphen.** A negative number in math is a real minus inside math mode (`$-5$`), not a text hyphen. ## Do / Don't - Never `\hline`; always `\toprule`/`\midrule`/`\bottomrule`. - Never a `|` in a column spec; always letters only (`{lcr}`). - Never put a table caption below the tabular; always above it. - Never put a figure caption above the graphic; always below it. - Never `[H]` or `[h!]`; always `[htbp]`. - Never a hyphen for a range; always an en-dash `--`. - Never the straight `"`; always `` ``...'' ``. - Never `...`; always `\ldots`. - Never `Figure \ref{}` with a space; always `Figure~\ref{}` with a tilde. - Never `10 ms` or `10ms`; always `10\,ms`. - Never inline `$\frac{}{}$`; always `\nicefrac{}{}`. - Never `$$...$$`; always `\[...\]`. - Never the letter `x` for multiply or `°` for degree; always `$\times$` and `$^\circ$`. - Never `\textbf`/`\textit`/color for prose emphasis; always `\emph{}`. - Never a bare `&`, `%`, `#`, `_`; always `\&`, `\%`, `\#`, `\_`. - Never a bare or `\texttt{}` URL; always `\url{}`. ## Common mistakes - Reaching for `\hline` and `|` columns — the universal novice default. - Writing the caption after the tabular (figure habit applied to a table). - Using a plain hyphen `10-20` for ranges; it reads as a subtraction. - Typing straight quotes `"..."` and literal `...` out of word-processor habit. - Omitting the tilde before `\ref`/`\cite` — the most common LaTeX mistake. - Gluing the unit to the number (`10ms`) or using a breakable plain space. - Using inline `$\frac{1}{2}$` mid-sentence and `$$...$$` for display math. - Using `\textbf{}` for emphasis because it "looks emphasized." - Forgetting to escape `&`/`%`/`#`/`_`, which silently breaks the build. ## Quick checklist booktabs rules · no `|` columns · table caption above · figure caption below · `[htbp]` · en-dash ranges · em-dash asides · `` ``...'' `` quotes · `\ldots` · tilde before refs/cites · `10\,ms` units · `\nicefrac` · `\[...\]` · `$\times$` / `$^\circ$` · `\emph{}` · escaped `\& \% \# \_` · `\url{}`.