• The first character before a ‘/’ that begins a comment must be whitespace (newline is OK).
  • Every line after the first in a multiline expressions must be indented.

The latter rule applies, for example, to functions. The following is not valid q:

f: {[x] x}

Even a function’s closing brace must be indented if it appears on a line by itself:

f: {[x] x

Function definition is not the only time you have to be careful to follow this rule, however. In the following example, g is not the list (47; 48); rather, g is a projection of the comma operator with its first argument set to 47:

g: 47,