A <Return> element is a statement block, and will stop execution of the policy rule, returning the value of the statement block as the value of the policy rule. In a policy rule, the <Return> should evaluate to a <PolicyRulePass> or <PolicyRuleFail> (see the section Pass/Fail Messages below).
<Return> <PolicyRulePass><Expr op='concat'><Expr value='VTY access-class '/><Expr variable='access-list'/><Expr value=' is set and defined'/></Expr></PolicyRulePass> </Return>