Humans normally have three kinds of cones. The first responds the most to light of long wavelengths, peaking at a reddish colour; this type is sometimes designated L for long. The second type responds the most to light of medium-wavelength, peaking at a green colour, and is abbreviated M for medium. The third type responds the most to short-wavelength light, of a bluish colour, and is designated S for short. The three types have peak wavelengths near 564–580 nm, 534–545 nm, and 420–440 nm, respectively, depending on the individual.[10][11] The difference in the signals received from the three cone types allows the brain to perceive a continuous range of colours, through the opponent process of colour vision. (Rod cells have a peak sensitivity at 498 nm, roughly halfway between the peak sensitivities of the S and M cones.)

All of the receptors contain the protein photopsin, with variations in its conformation causing differences in the optimum wavelengths absorbed.

The colour yellow, for example, is perceived when the L cones are stimulated slightly more than the M cones, and the colour red is perceived when the L cones are stimulated significantly more than the M cones. Similarly, blue and violet hues are perceived when the S receptor is stimulated more than the other two.

1) Make “gender” a more polite form of “sex”
2) Rewrite documents to use “gender” instead of “sex”
3) Define “gender” to be a personal choice and a social construction

Et voila, when someone says “men” they must have forgotten the transgendered and need to apologize.

What cracks me up is that people use gender all the time when they mean sex and do so because they think it is the polite thing to do. Then they fall into the trap of the definition of gender.

And they do talk about it.

He goes on:

“We recently programmed Bucket, the IRC chat bot in #xkcd, to allow people set their gender so he can use pronouns for them. This ended up taking hundreds of lines of code, three pages of documentation, and six different sets of pronouns and variables…”