I wish to edit the name key of a group of nodes to fix typos and normalize data. For instance, I want to change the first character of names places starting with "El " to "el ".
Currently I have a good filter rule in JOSM, so I can edit each node by hand easilly. But I would be easier selecting all desired nodes and replacing "El " to "el " with a single click. There are many typos in many nodes.
You’ll have to remove a lot for your purpose, but it’s all there; iterating over objects in the selection, regular expressions. I hope it can inspire you.