at some point in the history the example
{{#vardefine: i | 0 }}{{#while: | {{#ifexpr: {{#var: i }} < 5 | true }} |<nowiki/> * {{#var: i }}{{#vardefine: i | {{#expr: {{#var: i }} + 1 }} }} }}
changed to
{{#vardefine: i | 0 }}{{#while: | {{#ifexpr: {{#var: i }} < 5 | true }} | * {{#var: i }}{{#vardefine: i | {{#expr: {{#var: i }} + 1 }} }} }}
this, and other examples will only work with a the <nowiki /> tag to force a new line in the output but I don't feel qualified enough to provide a definitive answer as to which (or if there was a legitimate reason for their removal I haven't found)