Programmer's Guide > About This Guide > About This Guide > Conventions Used in This Guide
  
Conventions Used in This Guide
In addition to the conventions listed earlier, this guide uses the following notational conventions:
Square braces ([]) denote optional parameters which may be omitted. For example:
insertBefore(newChild[, refChild])
A vertical bar (|) separates parameters in a list from which one parameter must be chosen or used. For example:
allowinvalidmarkup {on | off}