...This tells vim-markdown whether to attempt to follow a named anchor in a link or not. When it is 1, and only if a link can be split in two parts by the pattern '#', then the first part is interpreted as the file and the second one as the named anchor. This also includes urls of the form #anchor, for which the first part is considered empty, meaning that the target file is the current one. After the file is opened, the anchor will be searched.