[vinodhn]

I still remember a scene from Seinfeld where George is at the unemployment office and when the lady asks him for the business's phone number, he says KL5 8383.

[dredmorbius]

An alias of the 555 fictitious exchange prefix, also sometimes KLamath 5 or KLondike 5:

<https://en.wikipedia.org/wiki/555_(telephone_number)>