Synopsis, one of:
\marginpar{right}
\marginpar[left]{right}
Create a note in the margin. The first line of the note will have the
same baseline as the line in the text where the \marginpar
occurs.
The margin that LaTeX uses for the note depends on the current layout
(see Document class options) and also on \reversemarginpar
(see below). If you are using one-sided layout (document option
oneside) then it goes in the right margin. If you are using
two-sided layout (document option twoside) then it goes in the
outside margin. If you are in two-column layout (document option
twocolumn) then it goes in the nearest margin.
If you declare \reversemarginpar then LaTeX will place
subsequent marginal notes in the opposite margin to that given in the
prior paragraph. Revert that to the default position with
\normalmarginpar.
When you specify the optional argument left then it is used for a note in the left margin, while the mandatory argument right is used for a note in the right margin.
Normally, a note’s first word will not be hyphenated. You can enable
hyphenation there by beginning left or right with
\hspace{0pt}.
These parameters affect the formatting of the note:
\marginparpush ¶Minimum vertical space between notes; default ‘7pt’ for ‘12pt’ documents, ‘5pt’ else. See also page layout parameters marginparpush.
\marginparsep ¶Horizontal space between the main text and the note; default ‘11pt’ for ‘10pt’ documents, ‘10pt’ else.
\marginparwidth ¶Width of the note itself; default for a one-sided ‘10pt’ document is ‘90pt’, ‘83pt’ for ‘11pt’, and ‘68pt’ for ‘12pt’; ‘17pt’ more in each case for a two-sided document. In two column mode, the default is ‘48pt’.
The standard LaTeX routine for marginal notes does not prevent notes from falling off the bottom of the page.