[TYPO3-english] TYPO3 6.2.x: if.isInList not working as expected

[Bert Hiddink [BENDOO e-work solutions]]

Hello,

I have a problem with if.isInList-statement

...
         renderObj.wrap.override.if {
              isInList.field = uid
              value.data = GP:tx_news_pi1|overwriteDemand|categories
         }
...

The override-statement turns true if I send fe from the browser 
"tx_news_pi1[overwriteDemand][categories]=1935".

If I send multiple values like this 
"&tx_news_pi1[overwriteDemand][categories]=1935,1923,9345" then it NEVER 
turns true.

Sending the value-string encoded like this "1935%2C1923" does not help, 
gives the same result.

According the docs this SHOULD work:
<https://docs.typo3.org/typo3cms/TyposcriptReference/Functions/If/Index.html>

if.isInList.field = uid
if.value = 1,2,34,50,87

Any ideas what might be the problem here?

Thanks in advance!
-brt