OHANDA, the Open Source Hardware and Design Alliance is an initiative to foster sustainable sharing of open hardware and design. The idea is for designers and manufacturers of open source hardware who wish their work to conform to the “Four Freedoms” of open source hardware to label their work the above “OH&A” insignia, thus making the openness visible to everyone.
The four freedoms, from the Free Software Definition, are:
Freedom 0: The freedom to use the device for any purpose.
Freedom 1: The freedom to study how the device works and change it to make it to do what you wish. Access to the complete design is precondition to this.
Freedom 2: Redistribute the device and/or design (remanufacture).
Freedom 3: The freedom to improve the device and/or design, and release your improvements (and modified versions in general) to the public, so that the whole community benefits. Access to the complete design is precondition to this.