The thing is, in your context, materials do matter; there are enourmous differences between material x and y, eg. a metal pipe and a plastic pipe. Different str

The thing is, in your context, materials do matter; there are enourmous differences between material x and y, eg. a metal pipe and a plastic pipe. Different structural capabilities, different resistance towards chemicals, etc., so if you do need clay pipes experience, because of the very special material that is about to flow in it, or due to structural/pressure/etc specialities, you may actually be in the need of someone who knows these. There aren't that many differences in software and they are easier to learn (eg. be aware of `killall` linux vs bsd). In this case though I doubt they were looking for a specialist; it would have been marked as, for example, AS/400 experience if this was the case.