There are certain phrases that stay with you long after the systems they described have been retired, rewritten, or quietly buried under layers of abstraction. One of them begins, with perfect IBM solemnity: “In a physically paired bidirectional logical relationship…” 1
That was the moment — the point on the road where many of us slowed down, frowned, and wondered whether we had accidentally joined a monastic order instead of a software team. The IMS manuals of the era were not written to be read so much as endured. They assumed you already understood the thing you were trying to learn, and if you didn’t, well, that was your problem.
At Rolls‑Royce, we lived inside these manuals — not because we wanted to, but because aero engines depended on the data, and the data depended on us understanding sentences like that one.
And then, just when you thought you’d survived the worst of it, you’d turn the page and encounter the other great artefact of the age: “This Page Intentionally Blank.”
A page that was not blank, announcing its blankness, and doing so with the tone of a legal deposition. It was the most honest lie in technical publishing. A contradiction printed in black ink, sitting there with the serene confidence of a Zen koan.
At Rolls-Royce, we used to joke that IBM must have had a whole department dedicated to paradoxes. The team that wrote the paragraph on physically paired bidirectional logical relationships probably sat next to the team that decided a page needed to declare its own emptiness. Both were products of the same mindset — a world where documentation was a physical object, where page numbers mattered, and where the safest thing you could do was explain everything, even nothing.
Looking back, these oddities feel like roadside markers on the long march through early database engineering. They remind us that the systems were complex, yes, but so were the people who tried to explain them. And sometimes, the most revealing thing in a manual wasn’t the architecture diagram or the pointer semantics — it was the quiet absurdity printed in the margins. Or the infuriating request in the feedback section at the back of the manual to, "Please avoid the use of anglicisms."