Calling return without specifying a value uses a value of 0. So, based on jim_yang's post, they would not function the same, as the first would return PLUGIN_CONTINUE.
Also note that a function can't return a value (ie: "return 1") and return nothing (ie: "return"). But, if you use the latter, then the compiler won't yell at you if you don't end your function with a return value.
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No longer around. Thanks your support, everyone! As always: