Del

Deletes All Currently Selected Elements From the Document

Strg+Shift+1 Starts the "Insert Measures" Tool
Strg+Shift+2 Starts the "Insert Staffdefs" Tool
Strg+Shift+4 Starts the "Score Image Export" Tool
Strg+Shift+5 Starts the "MEI-prune model" Tool
Strg+Shift+6 Opens the "Manage Sources" Dialog