You have to actually read the fare rules — the basis code doesn't usually tell you enough to be sure what the fare gets you.

I'll assume the fare text is almost identical for VHWRCIAW on the outbound portion and VHXRCIAW on the return portion.

These rules tell you that you can cancel your ticket (or even no-show and cancel afterward) and get back the entire price you paid for your ticket to your original form of payment, minus a €190 cancellation fee. (This is what United typically means by a "refundable" ticket, that you can voluntarily get some of the price you paid back to your original form of payment.)

These rules also tell you that you can change your ticket to any other United-issued ticket at any time for a €130 fee.

So the ticket is refundable (less a €190 fee) and changeable (less a €130 fee). If the fare rules are different on one of VHXRCIAW or VHWRCIAW then the 'worse' ones apply to the whole trip.

If you decide to cancel refund this ticket after it has been partially used, fore example you fly the outbound MIL-DEN and then decide you want to refund the DEN-MIL sector, then UA will compute the historical fare price of a one-way trip MIL-DEN. If this is cheaper than what you paid, you'll get a refund (minus €190 fee). If the new price is higher, UA may choose to ask you for more money (you should call them).