Interpreting alphanumeric code on power resistor
I would not bet the bank on this, but that code looks a lot like 5 watts, 0.03 ohms, which would be a good in-rush current limiter for a motor. A sign (sometimes the letter 'R') is placed between the ohms value to indicate it is 1 ohm or less, or a fractional value. The 'sign' is a virtual decimal point. Based on comments it could be a shunt resistor, or a burden resistor for a CT.
A white rectangle means it is wire-wound ceramic, which are very durable resistors and are designed to run too 'hot' to touch as a normal operating condition.
If the resistor gets too hot for long periods the code marked on it will burn away. A huge overload can make them crack open.
30 milliohms is difficult to measure without an expensive DVM. An option is a 1.00 amp constant current source, which would give you a 30 millivolt drop across the resistor. Little difference, as it is probably only 10% tolerance.
NOTE: Based on the chart I found it is a 5% tolerance resistor. About as good as it gets for off-the-shelf wire-wound.
I found this Resistor Tolerance Chart on the web.
(Reference IEC60062):
$$
\begin{array}{ccccccc}
Colour&amp; Value 1&amp; Value 2&amp; Value 3&amp; Multiplier&amp; Tolerance&amp; Letter Code\\
Silver &amp;&amp;&amp;&amp;x 0.01&amp; 10\% &amp; K\\
Gold&amp; &amp;&amp;&amp;x 0.1 &amp;5\% &amp;J\\
Black&amp; 0&amp; 0&amp; 0&amp; x1\\
Brown&amp; 1&amp; 1&amp; 1&amp; x10 &amp;1\% &amp;F\\
Red &amp;2 &amp;2 &amp;2 &amp;x 100 &amp;2\% &amp;G\\
Orange&amp; 3 &amp;3 &amp;3 &amp;x 1K&amp;\\
Yellow&amp; 4&amp; 4&amp; 4&amp; x 10K\\
Green&amp; 5&amp; 5&amp; 5&amp; x 100K &amp;0.5\% &amp;D\\
Blue&amp; 6&amp; 6 &amp;6 &amp;x 1M &amp;0.25\%&amp; C\\
Violet&amp; 7 &amp;7&amp; 7 &amp;x 10M &amp;0.1\%&amp; B\\
Grey&amp; 8 &amp;8 &amp;8 &amp;x 100M &amp;0.05\% &amp;A\\
White &amp;9 &amp;9 &amp;9 &amp;x 1G\\
Blank&amp;&amp;&amp;&amp;&amp; 20\%&amp; M 
\end{array}
$$