Template:!/doc

Documentation
This is an auxiliary template allowing to encode " " within template parameters. It is unnecessary to get a " "; " " is a better choice for this purpose. However, the " " delimiter for a Wiki table must be escaped by a template for use within a template; see also WP:QIF.

Note that there's no such problem with " " (exclamation mark), it only affects " " (vertical bar) in conjunction with the m:Help:Parameter_default mechanism within tables.

For obvious reasons this is a high risk template, and it cannot be substituted.