UCS is a command that sets a new user coordinate system (UCS) by specifying points or by selecting an object. You can use the Object option to align the UCS with a selected object such as a line.
Based on 3 and 4, UCSBASE is a system variable that sets the name of the current UCS base. PLINEGEN is a system variable that controls how linetype patterns are generated around vertices. LWEIGHT is a command that sets the current lineweight, which is used for new objects and affects objects in the current space only.
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