Spanish Practices

[airbolt]

In an Industrial setting workers or unions were often said to be employing " Spanish Practices ". What were these and how did the phrase come about?

[Clanad]

When used in the vernacular, means, generally, long standing but unauthorized working methods... largely viewed as vaguely, sometimes overtly racist.  A statement largely confined to European usage.  Uncommon in the U.S. I'm unsure of it's origin...

[Quizmonster]

This phrase started life in the form 'an old Spanish custom' in the 1930s. As Clanad rightly says, it refers to unauthorised working methods, though it has nothing to do with racism in British usage. The sort of situation it applied to was deliberate overmanning, excessive overtime and other means whereby employees took advantage of employers. (Given the centuries during which the boot was on the other foot...why not?)

As to why 'Spanish', it was probably in the same vein as we say 'Dutch courage' and 'French leave'; namely, making fun of old enemies.