A grammar expert has warned "if they take our apostrophes, commas will be next" after reports of councils culling punctuation from street signs.
Grammar campaigners have used marker pens to fill in allegedly missing apostrophes in Cambridge, after the city council ruled they should be removed to avoid confusing emergency services.
Kathy Salaman, director of the Cambridgeshire-based Good Grammar Company, said she knew who was responsible for the corrections.
She added: "I haven't done it myself but the person responsible has been in touch and they have my full support - I won't be outing them.
"If I was walking along with a marker pen in my pocket and I saw a missing apostrophe, it would be difficult to resist the temptation to fill it in."
The council has said it is following guidelines from the National Land and Property Gazetteer, where all new street names are registered.
It says that apostrophes can lead to mistakes, particularly on emergency service call outs.
A street sign reading "Scholars Way leading to Pepys Court and Fitzgerald Place" is among those which have been altered in marker pen, with apostrophes added to the words "Scholars" and "Pepys".
Ms Salaman said: "There is a serious side to this. I went to a state school in the 1970s and early 1980s and didn't learn grammar and that remains the case for many people.
"This is not about pedantry, it's about being able to write a sentence which can be easily understood.
"If children are surrounded by incorrect or contradictory grammar, it can be confusing. It could also teach them it isn't important.
"If they start getting rid of apostrophes now, commas will be next, then who knows what?"
The Cambridge City Council naming policy also bans street names which would be "difficult to pronounce or awkward to spell' and any which "could give offence" or would "encourage defacing of nameplates".
It does not apply to existing street signs.
Cllr Tim Ward, the executive councillor for planning, told the Cambridge News: "We are following national guidelines as requested by the emergency services.
"If they change their view we might change our policy, but it's not top of anybody's list of things to do."
Apostrophes are also banned in East Cambridgeshire and Huntingdonshire, but they are allowed in south Cambridgeshire.