.
With the option set, expanding selection (with e.g. Ctrl+Down) jumps to the end of the range in the column that was added to the initial selection the last. When the option is not set, expanding selection (with Ctrl+Down) jumps to the end of the range in the column where the initial selection was started.
Confirmed.
update: "With the option set, expanding a selection (with Ctrl+Shift+Down/Up) jumps to the end of the range in the column that was added as last to the initial selection. When the option is not set, expanding selection (with Ctrl+Shift+Down/Up) jumps to the end of the range in the column where selecting the cell range was started. The same of course applies when extending a selection on rows, with Ctrl+Shift+Left/Right"
patch in gerrit https://gerrit.libreoffice.org/#/c/61083/
Cor Nouws committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/help/commit/?id=8e6c3462c929a8ac34609f461ddc68684558c1d0 tdf#105034 add help text for option Position cell reference with selection