"{{{{{1}}}|{{{2}}}={{{3}}}}}" gives "{{{{{1}}}|{{{2}}}=}}" [1]
"{{{{{1}}}|{{{2}}}={{{3}}}}}"
See Help:Expansion demo templates.
Example:
{{xpdopec|3x|1|abc}} gives:
"{{3x|1=abc}}" gives "abcabcabc" [2]
"{{3x|1=abc}}"