anchor.diff:  channel specification that does not need a `:fine-offset` value).
   
   |:type
  -
   |Tells afterglow the kind of channel this is. Special values include
    `:color` for a channel that contains a color intensity, `:dimmer` for
    controlling brightness independent of color, and `:pan` and `:tilt`
  
positive.code: to match them up with the manual.
  
  |:fine-offset
  
  |There is one circumstance in which there _will_ be gaps in the
  `:offset` values for your channel definitions. Sometimes a pair of
  channels are used to express a single value, such as pan, tilt, or a
  
negative.code: 
  |:strobe
  
  |[[strobe-function]]Causes the fixture to flash on and off abruptly (and usually
   rapidly). This is typically a variable-range function, so different
   values within the function range cause the fixture to strobe at
   different speeds. If possible, use a `:scale-fn` function (with the
  