The inputs in a Flow board have messages that appear in the interface directionality; which means that if we look at the Hebrew Wikipedia with English interface, the bottom input would say, in English "Reply to: '... topic name...'".

However, those inputs are RTL aligned, which, especially if the topic is (or contains) English words, results in breaking the quotation marks, like this:

(The above is in a Hebrew Wiki but viewed with English interface)

This can be fixed by wrapping the placeholder with RLM/LRM entities. We can't do this in CSS because we don't want to override the input's 'direction' CSS property (The direction should still be RTL because the content is RTL) but the placeholder message itself should be isolated.