modify_footnote_symbol: Modify Footnote Symbols

In gtsummary: Presentation-Ready Data Summary and Analytic Result Tables

Modify Footnote Symbols

Description

• modify_footnote_symbol() customizes the symbols used to reference footnotes in a gtsummary table. By default, footnotes are referenced with sequential numbers (⁠1, 2, 3, ...⁠). This function replaces those numbers with a user-specified set of symbols, e.g. c("*", "\u2020", "\u2021") (an asterisk, dagger, and double dagger).

• remove_footnote_symbol() resets the footnote reference marks back to the default numbering.

Usage

modify_footnote_symbol(x, symbol)

remove_footnote_symbol(x)

Arguments

x

(gtsummary) A gtsummary object

symbol

(character) a character vector of length 2 or greater giving the ordered symbols used to reference footnotes, e.g. c("*", "\u2020", "\u2021"). Symbols are assigned to footnotes in the order the footnotes appear in the table. When the number of footnotes exceeds the number of symbols supplied, the symbols are recycled. A length of at least 2 is required because as_gt() passes these to gt::opt_footnote_marks(), which interprets a single string as the name of a built-in mark scheme. Currently only utilized by as_gt() and as_flex_table().

Details

The symbol sequence may also be set for all tables via the "pkgwide-chr:footnote_symbol" theme element; a value set with modify_footnote_symbol() takes precedence over the theme element.

Value

Updated gtsummary object

Common footnote marks

The table below lists common footnote reference marks and the R strings used to create them. The six marks correspond to those used in gt::opt_footnote_marks(marks = "extended"). Pass the R string (e.g. "\u2020") to the symbol argument to obtain the corresponding mark.

Name	Unicode	R string
asterisk	⁠U+002A⁠	"*"
dagger	U+2020	"\u2020"
double dagger	U+2021	"\u2021"
section sign	⁠U+00A7⁠	"\u00A7"
double vertical line	U+2016	"\u2016"
pilcrow (paragraph sign)	⁠U+00B6⁠	"\u00B6"

See Also

modify_footnote_header(), modify_footnote_body(), modify_footnote_spanning_header()

Examples

# use symbols (instead of numbers) to reference footnotes
trial |>
  tbl_summary(by = trt, include = c(age, grade), missing = "no") |>
  add_p() |>
  modify_footnote_symbol(symbol = c("*", "\u2020", "\u2021"))

gtsummary documentation built on Aug. 26, 2026, 9:07 a.m.