Yes it's probably clipboard.

Thanks for your welcome message.

Indeed there is an XML editor but inkscape formate the code to make it clear so you can't just use ctrl+c, ctrl+v ^^

Hi, First, sorry for my really bad english, I'm french. I tried to avoid mistakes but I'll probably make plenty of faults so... I apologize. Personally, I use a lot the XML code in Inkscape to make very precises diagram (like a diagram of a clock I made and which needed to make thinks very precisely...