User worries about compatibility each time he sees the words GNU make

[積丹尼 Dan Jacobson]

On (info "(make) Prerequisite Types") it says
   There are actually two different types of prerequisites understood by
   GNU 'make': normal prerequisites such as described in the previous
   section, and "order-only" prerequisites.

So one thinks "Ah, this (two different...) must be specific to GNU Make,
otherwise they would have said just 'make'."

But on
(info "(make) Features")
(info "(make) Missing")
we don't see anything related to this.

So it must be part of the 4.2 BSD baseline as mentioned on (info "(make)
Features").

But you got the reader worried.

But then again when writing the document one can't speak for all
makes... So maybe it is fine as is...

OK, maybe there are compatibility warnings already placed on pages that
need them.

But then pages that don't need them need "compatibility reassurance
notes" added.

OK, don't change anything. I just wanted to let you know some readers
might be worrying... (and don't want to have to dig into
(info "(make) Features")
(info "(make) Missing")
to double check each time.)