Currently its description is embedded in the LibreOffice - Security page, and makes it quite crowded: https://help.libreoffice.org/Common/Security_1 Also it might help the smaller problem reported in bug #100096 : In the Security Options and Warnings dialog pressing Help/F1 while OK, Cancel or Help is selected, it'll give totally uninformative results like this. https://help.libreoffice.org/swriter/cui/ui/securityoptionsdialog/ok?Language=en-US&System=WIN&Version=5.1
Gabor Kelemen committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/help/commit/?id=b20e40b89fc75992c9d790cc36699727d2d866f8 tdf#105280 Split out Security Options and Warnings help page