@test Verry good catch! My speed tests (Timeline in Google Chrome developer toools) give me a speed of 2.11 seconds without your patch. When I apply your patch the speeds is below 2 secondes, mostly 1.83 seconds.

One little note, please correct these and travis should be happy to

FILE: ...e/travis/build/joomla/joomla-cms/libraries/joomla/form/fields/rules.php
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FOUND 0 ERROR(S) AND 1 WARNING(S) AFFECTING 1 LINE(S)
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 269 | WARNING | Line exceeds 150 characters; contains 152 characters
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travis is most complicated part here

and question, related to the rule field,
what people think about make description always visible? ... instead of use tooltip

from:

to something like:

So user immediately see what rule for what....

Please make a new issue for that, so we can discuss it there.

Tanks for changing!
One more tester needed for this PR!

just asked, I not think that it is very important issue

I prefer tooltips. The are more clear for layout in my opinion. If you make the description directly visible it is to much information

Works great here

It saves from 1,2 -1,3 secs to 0,9 - 1,1 secs here

RTC based on testing. Thanks!

Merged. Thanks!