Usage

     {{indent|nn}}, takes a numeric argument 'nn' after the pipe and provides that many consecutive spaces. Indent differs from {{space}} only in that it automatically begins a newline, then spaces over 'nn' spaces.
   Consequently, this template can not be used inline to create alignment between adjacent text lines, or to space out titles, etc. Use {{space}} for such needs.

Related

Template:I (edit talk links history) calls indent with a default of three spaces, or passes on an argument if other padding is desirable whist remaining more compact
   (Very useful in tables where edit-jumble is a factor, or on talks to create indented paragraph beginings inside a wiki indented ':', '::', '::*', or a '#' prefixed line).