Standard HyperSpace distance unit

A standard HyperSpace distance unit is the unit of distance in HyperSpace. The correspondence between HS distance units and light-years, metres or any other common unit of measurement is unknown, though they may be identical or very close, as some sources indicate.¹

Notes and references

¹The Melnorme say that the Sentient Milieu spanned 500 light-years and that the Ur-Quan spreaded the Dnyarri through Milieu space in a month; since the Kohr-Ah fleet travels with a speed of 15.8 standard HyperSpace distance units per day (see here), in a month they cover 474 distance units, surprisingly close to 500.
However, Fwiffo gives the distance between Sol and Spathiwa as 143 light-years; the same distance can be measured as 233 HyperSpace distance units, giving the length of a HS unit as 0.61 light-years. Note that Fwiffo may simply be shortening the distance to convince The Captain to take him there for the ritual of Wezzy-Wezzah.