Used to detect possible lists. Useful for infoboxes, where the label may be singular (e.g., "Nickname:") but the data may be a list. One required parameter (the string to search for a list). Returns 1 if not a list, nil if a possible list.

Examples:

{{Detect singular|Mack the Knife}} → 1

{{Detect singular|Mack the Knife, Joe}}

{{Detect singular|{{hlist|first|second|third}}}}

{{Detect singular|[[Charles, Prince of Wales]]}}