TAG
A stylized name or signature done with various materials, such as a marker or an aerosol spray can, often freehand. Depending on its format or complexity, a tag may be called a throw-up, as in “that throw-up is amazingly detailed,” not as in “this Sharpie scrawl makes me want to throw up my cookies.” A person who tags is known as a writer or bomber.
I saw a couple of guys doing these type of tags freehand and amazingly quickly - I do not mind the artistic ones like this as long as they are not done over a piece of street art.
I can read kindergarteners script and scribble but have difficulty deciphering these lol