Footnotes & margin notes

Footnotes and margin notes are two ways to add an aside without interrupting the flow of your text. A footnote sends a numbered note to the bottom of the page; a margin note places a short note in the margin beside the body. This page covers \footnote and its split form \footnotemark / \footnotetext, tuning with the footmisc package, and margin notes with \marginpar and the marginnote package — each with where to reach for it and where it bites.

Footnotes — \footnote

The basic command is **\footnote{text}**. At the point where you write it, LaTeX places a superscript number (the footnote mark) and sets the matching text at the bottom of that page. The number is incremented automatically through the footnote counter, so you never assign it yourself.

What matters is placement. Because the mark should sit right after the word it annotates, write \footnote immediately after that word, with no space between them. A space or line break between the word and the command leaves that gap in the text and pushes the mark away from the word. Relative to punctuation, the mark normally goes after the punctuation.

TeX は 1978 年に生まれました\footnote{作者はクヌース。}。
その数式組版は今も標準です\footnote{arXiv も LaTeX を推奨。}。

To force a specific number, write **\footnote[num]{text}. Giving a number in brackets uses that number for the mark and does not** increment the footnote counter for that call — handy when two places should point at the same footnote.

The appearance of the number is governed by \thefootnote. To swap Arabic numerals for symbols (†, ‡, …), use \renewcommand{\thefootnote}{\fnsymbol{footnote}}. \fnsymbol maps 1–9 to an asterisk, dagger, and so on, so it suits documents with few notes. You can switch to \alph, \roman, and others the same way.

Splitting mark from text — \footnotemark / \footnotetext

\footnote only works correctly in outer paragraph mode. So in places like the inside of a **table (tabular), a \caption, the argument of a sectioning command (\section and friends), or a minipage**, the mark may fail to appear or the text may vanish. The escape hatch for these spots is a pair of commands that place the mark and the text separately.

• \footnotemark** — places only the mark (number) at that spot. With no argument it advances the footnote counter by one; \footnotemark[num] uses that number without advancing the counter.
• \footnotetext{text}** — places only the footnote body at the page bottom. Write it after \footnotemark, in a spot that is in outer paragraph mode; \footnotetext[num]{text} lets you match the number.

A typical pattern: inside the table, emit just the mark with \footnotemark, then write the body with \footnotetext{…} back in the body text after you leave the table (or minipage). To keep the numbers in sync it is safest to pin them explicitly, e.g. \footnotemark[7] paired with \footnotetext[7]{…}.

\begin{tabular}{ll}
  項目 A & 値\footnotemark[1] \\
  項目 B & 値 \\
\end{tabular}
\footnotetext[1]{この値は暫定です。}

Footnotes **inside a minipage are special**. There \footnote sets the note at the **bottom of that minipage** rather than the page bottom, the number is driven by the mpfootnote counter instead of footnote, and by default it shows as a lowercase letter (a, b, c…). In other words it is independent of the body footnote numbers and stays local to the minipage.

Tuning footnotes with footmisc

When you want finer control over the standard footnote behavior, load the well-established **footmisc** package. Put \usepackage[options]{footmisc} in the preamble and combine options to pick the behavior you want. The main ones:

It also reaches the margin. The gap between the mark and the footnote body (the footnote’s left margin) can be adjusted through the length **\footnotemargin** that footmisc provides — for example \setlength{\footnotemargin}{1.8em}.

\usepackage[perpage,bottom,multiple]{footmisc}
% ページごとに番号リセット＋最下部固定＋隣接マーク処理

Margin notes — \marginpar

To put a short note beside the body, use **\marginpar{text}**. A small note is set in the margin at the height where you wrote it. In two-sided layout (twoside) the note goes in the outer margin and automatically swaps sides between left-hand and right-hand pages.

To use different wording on each side, write **\marginpar[left]{right}. The bracketed [left] is the text used when the note falls in the left margin (a left-hand page); the braced {right}** is used when it falls in the right margin. To flip which side notes go to, use \reversemarginpar; to restore the default, \normalmarginpar.

But \marginpar carries strong limitations. Internally it is processed as a kind of float, like figures and tables, so it **cannot be used inside a float (figure/table), inside a footnote, or inside another \marginpar**. It also takes only one paragraph, and several notes on nearby lines may not align as you expect (they can overlap or shift).

The marginnote package — margin notes without the limits

When you want to sidestep those limits, use the **marginnote package’s \marginnote{text}. It does not use a float, so it can place a margin note even inside floats and footnotes**, where \marginpar cannot. As with \marginpar you can give per-side wording via \marginnote[left]{right}, and \reversemarginpar is honored.

On top of that, \marginnote takes a second optional argument for a vertical offset, written after the braces. The form is \marginnote[left]{right}[offset], where [offset] is a length: a negative value moves the note up, a positive value moves it down. This is handy for hand-spreading margin notes that would otherwise collide.

\usepackage{marginnote}
...
本文の脇に注を付けます\marginnote{これは傍注。}。
少し上げたい場合\marginnote{上にずらす}[-1\baselineskip]。

Note that \marginnote places the note at the height of the current line as-is, with none of the automatic collision-avoidance \marginpar attempts — so when notes overlap you nudge them with the offset above. In exchange for freedom from \marginpar’s float restrictions, it also has its own trade-offs (for instance, a \marginnote cannot break across a page).