Hi,
do you mean the network nodes such as https://www.openstreetmap.org/node/411034287? These are part of the way node networks are represented in OSM (see https://wiki.openstreetmap.org/wiki/Node_Networks), and they are used in various renderers (e.g. Waymarkedtrails and OsmAnd) and QA analyzers (e.g Knooppuntnet.nl). Please be careful not to break them, or the route relations that gather the ways between the network nodes.

Node networks are commonplace in the Netherlands, Belgium, Germany, France and (I believe) Switzerland. They are a major (and growing) way of organizing hiking routes, beyond loops and linear routes.