texlive-latex-framed 51265 Framed or shaded regions that can break across pages
The package creates three environments:
framed, which puts an ordinary frame box around the region,
shaded, which shades the region, and
leftbar, which places a line at the left side. The environments allow a break at their start (the
\FrameCommand enables creation of a title that is “attached” to the environment); breaks are also allowed in the course of the framed/shaded matter. There is also a command
\MakeFramed to make your own framed-style environments.