Design Rule
DRC Example :
¡ Text (SilkScreen) over a pad.
¡ Collision between components
PCB design is not simply placing components and creating connections. While designing a PCB we have to consider clearance between items like vias, tracks, pads,text, component placements etc.
You can check the design with the DRC form.

Elements checked :
The clearance between electrical elements E-E :
Trace-Trace | Trace - Pad | Pad - Pad | Trace - Slot
The clearance from electrical elements and board outline B-E :
Trace-BoardOutline | Pad-
BoardOutline
The clearance from electrical elements and e Mounting Hole M-E :
Trace - MHole | Pad - MHole
The clearance from electrical elements and Copper Pour C-E :
The clearance between components C-C :
Overlap of the text on the pad X-E :
DRC Settings
the free PCB Layout for your electronic projects
Different
Top-Bottom Clearance