how i stop urlrewriter stripping + symbols

i'm controlling intelligencia's urlrewriter concentration i'm carrying problem where manners i've setup seem stripping + representation url.

for instance i wish have urls /category/catname/+tag+tag nonetheless appears me /category/catname/ add-on tag

does anyone have any ideas down unchanging expression? i've attempted regulator matches fine.

<rewriter>
  <rewrite url="^/content/(.+)$" to="~/page.aspx?name=$1" />
  <rewrite url="^/category/(.+)$" to="~/catalog.aspx?category=$1" />
  <rewrite url="^/product/(.+)$" to="~/catalog.aspx?product=$1" />
  <rewrite url="~/login/" to="~/login.aspx"/>
</rewriter>