I was wrong. The \penalty is not the culprit, but it turns out to be the \Word macro that introduces the <break/> through a parfillskip_code in the internal list.

dr. Hans van der Meer


> On 5 Mar 2020, at 09:33, Hans van der Meer <havdmeer@ziggo.nl> wrote:
> 
> Found the cause in my case: a \penalty0 statement.
> 
> dr. Hans van der Meer


> On 3/3/2020 16:51, Hans van der Meer wrote:
>> In producing epub <break/>s are appearing (on the -raw.xml file) that are unwanted and seem spurious to me. For example aftersome macro's. 
>> Can someone tell me what triggers a <break/>? In the pdf output such breaks are absent.
>> 
>> dr. Hans van der Meer
>>