Build or select a table style

A style is a small set of number-formatting rules – how many decimals a p-value gets, where it bottoms out, whether it keeps its leading zero, what the decimal mark is, how a confidence interval is written. spicy_style() composes one by hand; the named themes ("jama", "nejm", "lancet", "annals", "apa", "aer", "fr" – spicy_style_names() returns the list) are pre-composed ones, each encoding rules taken verbatim from an official document of the institution.

Usage

spicy_style(
  base = NULL,
  ...,
  p_style = NULL,
  p_digits = NULL,
  p_floor = NULL,
  p_bands = NULL,
  p_sigfig = NULL,
  decimal_mark = NULL,
  ci_sep = NULL,
  ci_brackets = NULL,
  stars = NULL,
  digits = NULL,
  effect_size_digits = NULL,
  fit_digits = NULL,
  ic_digits = NULL,
  percent_digits = NULL,
  v_digits = NULL
)

spicy_style_names()

Arguments

base: Optional theme to start from – a theme name or another spicy_style – whose levers the arguments below override. This is the composition escape hatch: spicy_style("lancet", ci_sep = " to ") is The Lancet's rules with one of them changed. The theme's provenance travels with the result and names the levers you overrode, so a modified theme never passes for the theme itself.
...: Must be empty. Any argument landing here is a misspelt lever and raises an error rather than being ignored.
p_style: How p-values carry their leading zero: "apa" drops it (.003), "standard" keeps it (0.003). NULL leaves spicy's default, which drops it.
p_digits: Decimal places for p-values (a positive integer). Under p_sigfig it acts as the decimal cap instead.
p_floor: The value below which a p-value prints as <floor rather than exactly, e.g. 0.001 for <.001. A number strictly between 0 and 1. NULL uses 10^-p_digits.
p_bands: Decimal places that vary with the size of the p-value: a list of two-element numeric vectors c(cutoff, digits), cutoffs strictly increasing, the last one Inf. list(c(0.01, 3), c(Inf, 2)) reads as "three decimals below .01, two otherwise". The comparison is p < cutoff. Mutually exclusive with p_sigfig.
p_sigfig: Significant figures for p-values (a positive integer), capped at p_digits decimal places. Mutually exclusive with p_bands.
decimal_mark: A single character; the mark between the integer and the decimal part of every number in the table.
ci_sep: The string between the two bounds of a confidence interval. NULL keeps spicy's default, which is ", " and turns into "; " when the decimal mark is a comma.
ci_brackets: A character vector of length two, the opening and closing delimiters of a confidence interval, e.g. c("[", "]") or c("(", ")").
stars: Significance stars: FALSE to suppress them, or a named numeric vector of symbol-to-threshold pairs such as c("***" = .001, "**" = .01, "*" = .05).
digits, effect_size_digits, fit_digits, ic_digits: Decimal places for estimates, effect sizes, fit statistics and information criteria. Each is applied only by the table functions that have the matching argument.
percent_digits, v_digits: Decimal places for percentages and for the association measure of table_categorical().

Value

spicy_style() returns an object of class spicy_style: a named list holding only the levers that were set. Themes returned by name carry a provenance attribute with the journal, its source document and the exact list of encoded rules; print() shows it. spicy_style_names() returns the character vector of available theme names.

Details

A style is accepted by the style argument of table_regression(), table_categorical(), table_continuous() and table_continuous_lm(), either as a theme name or as the object returned here, and by options(spicy.style = ) for document-wide scope.

What a theme claims, and what it does not

A theme covers numeric formatting conformity only – not full editorial conformity. It does not check reporting guidelines, table structure, footnote symbols, units, abbreviation policy, or anything else a journal's instructions ask of a manuscript. Each theme below lists the exact rules it encodes, with the sentence it encodes them from; anything not listed is spicy's own default, not the journal's rule.

Themes only move defaults. An argument you type wins over the theme, always: table_regression(fit, style = "lancet", digits = 3) is a Lancet table with three decimals. One consequence worth stating: typing p_digits is a request for that many decimals on every p-value, so it also switches off the theme's own ways of choosing p-precision – p_bands, p_sigfig, and the p_floor derived from them. The leading-zero rule is orthogonal and stays.

Resolution order

style argument, then getOption("spicy.style"), then spicy's defaults. Within a style, an explicit function argument beats the style's value for the same lever.

Themes

`"jama"` – JAMA / JAMA Network

Source: Instructions for Table Creation, JAMA Network author document, 23 February 2016 (https://jamanetwork.com/DocumentLibrary/InstructionsForAuthors/InstructionsForTableCreation.pdf), consulted 2026-08-14.

Encoded:

p-values on two decimals, three below .01, floored at <.001, with no leading zero – "All P values should be reported to exact numbers to 2 digits past the decimal point, regardless of statistical significance. For values lower than .01, present the P value to 3 digits. Express any values lower than .001 as P<.001."

Not encoded: everything else in that document (percentages carrying their numerator and denominator, one datum per cell, footnote letters, SI conversion factors) is table construction, not number formatting. The document states no rule for the confidence-interval separator or the decimal mark, so spicy's defaults apply.

`"nejm"` – The New England Journal of Medicine

Source: NEJM Author Center, New Manuscripts, section Statistical Reporting Guidelines (https://www.nejm.org/author-center/new-manuscripts), a living page; its full text was read in a browser by the package maintainer on 2026-08-14 – the site refuses automated retrieval, which is why earlier surveys reported these rules as unavailable.

Encoded:

tiered p-values, leading zero kept – "In general, P values larger than 0.01 should be reported to two decimal places, and those between 0.01 and 0.001 to three decimal places; P values smaller than 0.001 should be reported as P<0.001." The guideline's own text writes 0.01 / 0.001: unlike JAMA, the leading zero stays.
measures of association on two decimals – "measures of association, such as odds ratios, should ordinarily be reported to two decimal places" (a pin of spicy's default).

Not encoded: the guideline's stated exceptions to the p rule (stopping-rule tests, genomewide studies) are analysis contexts the style layer cannot see; its inference policy (no p-values without a prespecified multiplicity plan, estimates + 95% CI instead, no p-values in the Table 1 of a randomised trial) is about what to report, not how to format it – request those layouts through show_columns and p_value = FALSE where you need them.

`"lancet"` – The Lancet

Sources: Information for Authors, April 2026; Randomised trials in The Lancet: formatting guidelines and Observational studies in The Lancet: formatting guidelines, both last updated July 2025 (https://www.thelancet.com/pb-assets/Lancet/authors/tl-info-for-authors-1690986041530.pdf), consulted 2026-08-14.

Below, the journal's midline decimal point (Unicode U+00B7, MIDDLE DOT) is written [.] so it cannot be confused with an ordinary full stop.

Encoded:

midline decimal mark, U+00B7, on every number in the table – "Type decimal points midline (ie, 23[.]4, not 23.4)."
p-values on two significant figures, capped at four decimals, floored at p<0[.]0001, leading zero kept – "Supply p values to two significant figures (capped at four decimal places), or p<0[.]0001."
en dash between the bounds of a confidence interval. This one is not a written rule: the journal states none. It matches the intervals printed throughout the journal's own model tables and figures (0[.]78 (0[.]60-1[.]00)) and is encoded as conformity to the journal's published examples, nothing stronger.

Not encoded: the empty-cell filler, the ban on p-values in a randomised trial's baseline table, and the absolute-rather-than- relative effect rule are content decisions, not number formats.

One caveat on the en dash. The journal's examples are ratio measures, whose bounds are positive. On the identity scale a negative lower bound puts a minus sign next to the dash ([-5.17--2.58]), which reads badly. The journal states no rule for that case and none is invented here; override the separator when it arises: spicy_style("lancet", ci_sep = " to ").

`"annals"` – Annals of Internal Medicine

Source: Information for Authors, American College of Physicians, document publication date 08/04/2026 (https://www.acpjournals.org/pb-assets/pdf/AnnalsAuthorInfo-1755188286957.pdf), consulted 2026-08-14.

Encoded:

p-values on three decimals up to 0.20 and two decimals above it, floored at P<0.001, leading zero kept – "For P values between 0.001 and 0.20, please report the value to the nearest thousandth. For P values greater than 0.20, please report the value to the nearest hundredth. For P values less than 0.001, report as 'P<0.001.'"

Not encoded: the percentage rule ("Report percentages to one decimal place ... when sample size is \(\ge\) 200", no decimals below 200) is conditional on a per-group sample size that the style layer does not see; set percent_digits yourself. The mean (SD) notation the journal asks for, and its refusal of \eqn{\pm}{+/-}, are already how spicy renders dispersion.

`"apa"` – APA Style, 7th edition

Sources: APA Style numbers and statistics guide, last updated 11 September 2024 (https://apastyle.apa.org/instructional-aids/numbers-statistics-guide.pdf); Sample tables, last updated June 2024 (https://apastyle.apa.org/style-grammar-guidelines/tables-figures/sample-tables), both consulted 2026-08-14.

Encoded – and this theme pins rather than changes: spicy's defaults already follow the guide, so style = "apa" is a promise that a future change of those defaults will not move an APA-formatted table.

p-values on three decimals, floored at <.001, no leading zero – "Report exact p values to two or three decimals (e.g., p = .006, p = .03)", "report p values less than .001 as 'p < .001.'", and "Do not use a zero before a decimal when the statistic cannot be greater than 1 (proportion, correlation, level of statistical significance)."
estimates and dispersion on two decimals – "Report other means and standard deviations and correlations, proportions, and inferential statistics (t, F, chi-square) to two decimals."
confidence intervals in square brackets, bounds separated by a comma – the Sample tables page gives 95% CI [LL, UL] as one of the two official layouts.

Not encoded: the one-decimal rule for means of integer scales (depends on what the variable measures, which spicy cannot know), and the thousands separator (see Known gaps below). Nor the star thresholds. The official correlation and ANOVA sample tables mark .05 / .01 / .001, which is what stars = TRUE gives you – but as spicy's own default, not as anything this theme pins: one stars lever carries both the thresholds and the decision to show them, and the APA regression sample table shows none. So the theme sets no stars, and style = "apa" never switches them on.

`"aer"` – American Economic Review / AEA journals

Source: AER Style Guide, American Economic Association (https://www.aeaweb.org/journals/aer/style-guide), consulted 2026-08-14. The Tables section is shared with AEJ: Applied, AEJ: Macro, AEJ: Policy, JEL and AEA P&P.

Encoded:

leading zero on every decimal fraction, p-values included – "Place a zero in front of the decimal point in all decimal fractions (e.g., 0.357, not .357)."
no significance stars, pinned – "Do not use asterisks to denote significance of estimation results. Report the standard errors in parentheses." This is the only outright written ban on stars in the whole surveyed corpus, so it is encoded even though spicy already defaults to stars = FALSE. Ask for show_columns = c("b", "se") for the standard-error layout.

Not encoded: the guide fixes no number of decimals, no p-value floor, no interval format and no decimal mark, so spicy's defaults apply. Horizontal-rules-only, no shading, a nine-column maximum and "Panel A / Panel B" blocks are layout, not number formatting.

`"fr"` – French-language typography (a locale, not a journal)

Sources: BIPM, Le Systeme international d'unites, 9th edition, 2019, section 5.4.4 (https://www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf); European Union, Code de redaction interinstitutionnel, French edition 2022, point 6.5 (https://style-guide.europa.eu/fr); both consulted 2026-08-14.

Encoded:

comma as the decimal mark – "La virgule est utilisee pour separer les unites des decimales" (EU, 6.5); the SI brochure leaves the choice to the language: "Le separateur decimal choisi sera celui qui est d'usage courant selon la langue concernee et le contexte."
leading zero kept, p-values included – "Si le nombre se situe entre +1 et -1, le separateur decimal est toujours precede d'un zero : par exemple, -0,234 mais pas -,234" (SI, 5.4.4). This is what makes the theme worth having: with only decimal_mark = ",", spicy would print a p-value as ,003.

The semicolon that separates interval bounds under a comma decimal mark is spicy's own disambiguation rule, not a sourced one; it follows from decimal_mark and needs no entry here.

Known gaps

Two rules the sources state but this release does not encode:

thousands separator (APA's comma, the EU code's thin no-break space). spicy formats numbers through more than one path, and a separator applied to some of them only would print 1,234 in one column and 1234 in the next – the exact inconsistency the SI brochure forbids ("the format used should not vary within one column").
significant-figure rounding of estimates (Epidemiology's nn / n.n / 0.nn, Science's "report only significant digits"). spicy's digits is a decimals contract applied per column family; a blanket significant-figure mode would also round fit statistics, which those rules do not ask for.

Journals deliberately absent: BMJ (its house-style page could not be read from any official source, and the widely repeated "95% CI 1.2 to 3.4" rule traces to no BMJ document), Econometrica (verified negative: the official guidelines contain no numeric table rule), QJE (its instructions page could not be read), Epidemiology (see Known gaps). Naming any of them would mean inventing their rules.

Examples

fit <- lm(mpg ~ wt + hp, data = mtcars)

# A named theme.
table_regression(fit, style = "jama")
#> Linear regression: mpg
#> 
#>  Variable    │   B     SE       95% CI        p   
#> ─────────────┼────────────────────────────────────
#>  (Intercept) │ 37.23  1.60  [33.96, 40.50]  <.001 
#>  wt          │ -3.88  0.63  [-5.17, -2.58]  <.001 
#>  hp          │ -0.03  0.01  [-0.05, -0.01]   .001 
#> ╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌
#>  n           │ 32                                 
#>  R²          │  0.83                              
#>  Adj. R²     │  0.81                              
#> 
#> Note. Linear regression.
#> Std. errors: classical (OLS).

# An argument you type beats the theme.
table_regression(fit, style = "jama", p_digits = 4)
#> Linear regression: mpg
#> 
#>  Variable    │   B     SE       95% CI        p    
#> ─────────────┼─────────────────────────────────────
#>  (Intercept) │ 37.23  1.60  [33.96, 40.50]  <.0001 
#>  wt          │ -3.88  0.63  [-5.17, -2.58]  <.0001 
#>  hp          │ -0.03  0.01  [-0.05, -0.01]   .0015 
#> ╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌
#>  n           │ 32                                  
#>  R²          │  0.83                               
#>  Adj. R²     │  0.81                               
#> 
#> Note. Linear regression.
#> Std. errors: classical (OLS).

# A style composed by hand.
table_regression(fit, style = spicy_style(decimal_mark = ",",
                                          p_style = "standard"))
#> Linear regression: mpg
#> 
#>  Variable    │   B     SE       95% CI        p    
#> ─────────────┼─────────────────────────────────────
#>  (Intercept) │ 37,23  1,60  [33,96; 40,50]  <0,001 
#>  wt          │ -3,88  0,63  [-5,17; -2,58]  <0,001 
#>  hp          │ -0,03  0,01  [-0,05; -0,01]   0,001 
#> ╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌
#>  n           │ 32                                  
#>  R²          │  0,83                               
#>  Adj. R²     │  0,81                               
#> 
#> Note. Linear regression.
#> Std. errors: classical (OLS).

# A theme with one rule changed.
table_regression(fit, style = spicy_style("lancet", ci_sep = " to "))
#> Linear regression: mpg
#> 
#>  Variable    │   B     SE        95% CI          p    
#> ─────────────┼────────────────────────────────────────
#>  (Intercept) │ 37·23  1·60  [33·96 to 40·50]  <0·0001 
#>  wt          │ -3·88  0·63  [-5·17 to -2·58]  <0·0001 
#>  hp          │ -0·03  0·01  [-0·05 to -0·01]   0·0015 
#> ╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌
#>  n           │ 32                                     
#>  R²          │  0·83                                  
#>  Adj. R²     │  0·81                                  
#> 
#> Note. Linear regression.
#> Std. errors: classical (OLS).

# Document-wide scope.
old <- options(spicy.style = "apa")
table_continuous(mtcars, c(mpg, wt))
#> Descriptive statistics
#> 
#>  Variable   │    M       SD      Min      Max     95% CI LL    95% CI UL    n   
#> ────────────┼───────────────────────────────────────────────────────────────────
#>  mpg        │  20.09    6.03    10.40    33.90      17.92        22.26      32  
#>  wt         │   3.22    0.98     1.51     5.42       2.86         3.57      32  
options(old)

# What a theme encodes, and where it comes from.
spicy_style("lancet")
#> <spicy_style> "lancet" -- The Lancet
#> 
#> Encoded rules (numeric formatting only, not editorial conformity):
#>  - decimal mark: midline dot U+00B7 on every number
#>  - p-values: 2 significant figures capped at 4 decimals, floor <0·0001, leading zero kept
#>  - confidence intervals: en dash between bounds (matches the journal's published examples; not a written rule)
#> 
#> Source: Information for Authors (April 2026); Randomised trials / Observational studies formatting guidelines (July 2025)
#>         https://www.thelancet.com/pb-assets/Lancet/authors/tl-info-for-authors-1690986041530.pdf
#>         2026-04, consulted 2026-08-14
#> 
#> Levers:
#>   p_style             standard
#>   p_digits            4
#>   p_floor             0.0001
#>   p_sigfig            2
#>   decimal_mark        ·
#>   ci_sep              –

Usage

Arguments

Value

Details

What a theme claims, and what it does not

Resolution order

Themes

"jama" – JAMA / JAMA Network

"nejm" – The New England Journal of Medicine

"lancet" – The Lancet

"annals" – Annals of Internal Medicine

"apa" – APA Style, 7th edition

"aer" – American Economic Review / AEA journals

"fr" – French-language typography (a locale, not a journal)

Known gaps

Examples

`"jama"` – JAMA / JAMA Network

`"nejm"` – The New England Journal of Medicine

`"lancet"` – The Lancet

`"annals"` – Annals of Internal Medicine

`"apa"` – APA Style, 7th edition

`"aer"` – American Economic Review / AEA journals

`"fr"` – French-language typography (a locale, not a journal)