There's the well-known case of Spain in 1985, that would impose a tariff on computers with 64 KB RAM or less. At that time, Amstrad launched the CPC 464 with 64KB worldwide, but for Spain launched the special model CPC 472, wich had a daughter board with an additional 8Kb chip not connected to the main RAM and thus unusable, but enough for circumventing the tariff. That tariff was short-lived.