anchor.diff:  many LISPs used to denote _special vars_. Most commonly in Clojure this is
   used to denote _dynamic_ vars, i.e. ones that can change depending on
   dynamic scope. The earmuffs act as a warning that "here be dragons"
  -and to never assume the state of the var. Remember, this is a _convention_, not a
  +and to never assume the state of the var. Remember, this is a convention, not a
   rule.
   
   Core Clojure examples include `\*out*` and `\*in*` which represent the standard in
  
positive.code: 1
  ----
  
  This is simply a recommended _convention_ and not a requirement.
  
  Note that the exclamation mark is often pronounced as bang.
  
  
negative.code: == `_` - Unused argument
  
  When you see the underscore character used as function arguments or in a `let` binding,
  `pass:[_]` is a common naming convention to indicate you won't be using this argument.
  
  This is an example using the `add-watch` function that can be used to add
  callback style behaviour when atoms change value. Imagine, given an atom, we
  