Mizter T wrote:
Like the sub-surface Underground lines, my unneccesary apostrophe
filter appears to be suffering from poor performance because of the
heat. I shall take the advice of the Tube station posters and drink
some water before I continue my journey on usenet.

It could be argued that words endin in -co as an abreviation for company
could legitmately be made plural by co's as a contraction of companies.
Of course if you were doing that, you should probably write it infra'co's.

Robin