{not available when compiled without the |+folding| feature} Sets 'foldlevel' when starting to edit another buffer in a window. Useful to always start editing with all folds closed (value zero), some folds closed (one) or no folds closed (99). This is done before reading any modeline, thus a setting in a modeline overrules this option. Starting to edit a file for |diff-mode| also ignores this option and closes all folds. It is also done before BufReadPre autocommands, to allow an autocmd to overrule the 'foldlevel' value for specific files. When the value is negative, it is not used.