Normally, there is no vertical spacing between the label of an item in one of the standard lists and the following text – only a horizontal spacing, namely \labelsep
and \itemindent
.
However, as mentioned by @GuM, you can manage to have a line break manually, and it's up to you to add such a spacing. This is easy for enumerate
and itemize
, writing \leavevmode\\[some verticalskip]
just after \item
.
Unfortunately it doesn't work for description
environments. I propose a solution, which consists in defining a new Description
environment for which the \descriptionlabel
command is redefined to incorporate an invisible rule below the base line. The length of this rule is an optional argument of the environment (rather arbitrary default: 3mm). Thanks to xparse
, the environment accepts a second optional argument, for the set of key = some value
to be handed to the description
environment.
Here is an example:
\documentclass{article}%
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[svgnames]{xcolor}
\usepackage{lipsum}
\usepackage{enumitem}
\setlist[description]{leftmargin = 12mm}
\usepackage{xparse}
\NewDocumentEnvironment{Description}{O{3mm}O{}}{\renewcommand*\descriptionlabel[1]{\rule[-#1]{0pt}{#1}\hspace\labelsep
\normalfont\bfseries ##1}\description[style =standard, labelwidth=\textwidth, #2]}{\enddescription}
\begin{document}
‘Force next line’:
\begin{Description}[1.8ex][font=\sffamily\color{FireBrick!60}]
\item[One]\lipsum[4]
\item[And another one] \lipsum[4]
\end{Description}
\end{document}

\leavevmode\\*[\smallskipamount]
(say) just after the closing bracket of the relevant\item[...]
command.\smallskipamount
with, say,1pt
. Can't I avoid that somehow?