https://www.w3schools.com/jsrEF/met_document_execcommand.asp
HTML DOM Document execCommand() Method
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html domdocumentexeccommandmethod
https://quirksmode.org/dom/execCommand.html
execCommand compatibility
execcommandcompatibility
https://caniuse.com/?search=document.execCommand%20copy
"document.execCommand copy" | Can I use... Support tables for HTML5, CSS3, etc
"Can I use" provides up-to-date browser support tables for support of front-end web technologies on desktop and mobile web browsers.
can i use