Continuing the discussion from Why are you learning Welsh? :
My favourite aunt, a first-language Welsh speaker, told me once about being forced to wear some sort of sign around her neck at school for being caught speaking Welsh in the school yard. She never learned to read or write her own language, which is such a shame.
Ah, the (in)famous Welsh Not. (Or at least that’s the name I’ve heard for that sign.)
The historical consensus (incl. John Davies, prominently) is that the Welsh Not was not used as extensively as was once believed, and that its use ended when elementary education started to be through the medium of welsh after 1870.
The Welsh Not (also Welsh Knot, Welsh Note, Welsh Stick, Welsh Lead or Cwstom) was an item used in Welsh schools in the 18th, 19th and 20th centuries to stigmatise and punish children using the Welsh language.
"Endeavoured to compel the children to converse in English by means of a piece of wood. Offenders to be shut in after school hours."
Extracts from the Llansantffraid board school log book.
8th February, 1870.
Typically "The Not" was a piece of wood, a ruler or a stick, often inscribed wi...
http://www.bbc.co.uk/wales/history/sites/themes/society/language_education.shtml