Vector conversion of File:Quatrefoil-Architectural-Square.png; original description of that image follows:
An architectural/symbolic "quatrefoil" (consisting of four overlapping circles) combined with a square.  For forms of the quatrefoil, see Image:Quatrefoil-Architectural-alternate.png and Image:Quatrefoil-Architectural.png.

The architectural quatrefoil combined with a square is the fourfold version of an architectural trefoil combined with an equilateral triangle (see Image:Trefoil-Architectural-Equilateral-Triangle-outlined.png and Image:Trefoil-Architectural-Equilateral-Triangle-interlaced.png).
Generated by means of the following PostScript code:

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a 306 534 x add a 306 258 x sub
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2 mul rlineto d 2 mul 0 rlineto
0 d -2 mul rlineto fill}def
/c{163}def/d{232}def b 1 setgray
/c{157}def/d{226}def b 0 setgray
/c{144}def/d{213}def b 1 setgray
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%EOF
Raster image and vector source by AnonMoos, initial vector image by Flanker