`d` - Data. For UPC or EAN, use `*` for missing digit. For Codabar, use `ABCD` or `ENT*` for start and stop characters. For QR, encode in Shift-JIS for kanji mode.
`pv` - Top and bottom padding. Default is value of `p`.
`ph` - Left and right padding. Default is value of `p`.
`pt` - Top padding. Default is value of `pv`.
`pl` - Left padding. Default is value of `ph`.
`pr` - Right padding. Default is value of `ph`.
`pb` - Bottom padding. Default is value of `pv`.
`bc` - Background color in `#RRGGBB` format.
`cs` - Color of spaces in `#RRGGBB` format.
`cm` - Color of modules in `#RRGGBB` format.
`tc` - Text color in `#RRGGBB` format. Applies to linear barcodes only.
`tf` - Text font for SVG output. Default is monospace. Applies to linear barcodes only.
`ts` - Text size. For SVG output, this is in points and the default is 10. For PNG, GIF, or JPEG output, this is the GD library built-in font number from 1 to 5 and the default is 1. Applies to linear barcodes only.
`th` - Distance from text baseline to bottom of modules. Default is 10. Applies to linear barcodes only.
`ms` - Module shape. One of: `s` for square, `r` for round, or `x` for X-shaped. Default is `s`. Applies to matrix barcodes only.
`md` - Module density. A number between 0 and 1. Default is 1. Applies to matrix barcodes only.
`wq` - Width of quiet area units. Default is 1. Use 0 to suppress quiet area.
`wm` - Width of narrow modules and spaces. Default is 1.
`ww` - Width of wide modules and spaces. Applies to Code 39, Codabar, and ITF only. Default is 3.
`wn` - Width of narrow space between characters. Applies to Code 39 and Codabar only. Default is 1.