Shape tag “” in draw.io. Where can I find any documentation

For now there's a URL parameter libs that takes a semicolon separated list of the library sets you want, e.g.:

https://www.draw.io/?libs=general;flowchart;basic;arrows;clipart;signs;mockups;electrical;aws;pid;leanMapping;cisco

That's also the list of all possible values currently for that parameter. You've made me realise there's a bug with ER, BPMN and iOS sets regarding this, we'll look at that.

We have discussed this and intend to persist the library settings between uses. A question for you, would you prefer this to be stored per browser (i.e. cookies) or per Google account (as a meta file in your Drive)?

The underlying library does have this, we just never assigned it to a key. We've switched it on now and assigned it to the shift key.