Modx 2 syntax

[ [...] ] - Calling snippet

[ [$...] ] - Calling chunk

[ [*...] ] - output / return modx setting or page variable, example [ [*pagetitle] ], [ [*content ] ]

[ [+...] ] - output / return variable from snippet call into chunk

[ [!... ] ] - Calling snippet without cache

[ [%...] ] - output Lexicon value (language)