A drive to save time answering 999 calls could be behind the growing number of councils choosing to drop punctuation from street signs in a move which is horrifying self-declared defenders of grammar.
Campaigners in Cambridge have taken matters in hand, using marker pens to fill in allegedly missing apostrophes after the city council ruled they should be removed to avoid confusing emergency services.
Elsewhere, there have been reports of criticism of a similar policy adopted by East Staffordshire Borough Council in the Midlands.
In Cambridge, the guerrilla tactics adopted by an anonymous pen-smith has been backed by one grammar expert who warned "if they take our apostrophes, commas will be next".
However, councils say the change is in line with national guidance which is, in part, designed to make it easier for the emergency services to get to the right addresses when responding to 999 calls.
The appearance of more and more street signs without punctuation has stemmed from the need for an accurate national database of every address in the UK, managed by GeoPlace.
GeoPlace was set up jointly by the Local Government Association, which represents local authorities in England and Wales, and the UK's national mapping authority, the Ordnance Survey, in 2011 to answer the need for such a list, known as the National Land and Property Gazetteer.
It is the gazetteer data which is used by 999 call handlers in dispatching emergency vehicles, when every second counts.
Councils are now asked to routinely submit data on new streets to the organisation, but are still free to set their own policy when naming roads, according to GeoPlace.
A spokesman for GeoPlace added that while it does not specifically ask councils to remove or include punctuation, it prefers not to have it sent as it can confuse the machines which read the submitted data but can also save time when dispatching ambulances or police to 999 calls.
The row over apostrophes shows little sign of abating soon, and on the frontline in Cambridge the actions of the anonymous individual carrying out the corrections has been backed by an expert in the field.
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."
A street sign in the city 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.
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."
A spokesman for East Staffordshire Borough Council told the Burton Mail: "The council does not use apostrophes when introducing new street names, but they have existing street names within the borough which historically have included them.
"The reason for the change is potential problems this could cause with records on databases."
Apostrophes are also banned in East Cambridgeshire and Huntingdonshire, but they are allowed in South Cambridgeshire.
A spokesman for GeoPlace said: "Local authorities will have their own policy for the naming of streets and the numbering of properties.
"GeoPlace does not advise that councils include or remove punctuation in official naming or on the street name plate. Street naming and numbering is a council policy decision.
"However, the data entry conventions documentation does state that GeoPlace would prefer not to receive data, including street names, with punctuation.
"This is for two main reasons; machine readability, as punctuation can be misinterpreted by computers.
"Secondly, usability - for example, if loaded into an emergency service command and control system and a caller provides a street name, the search will be faster if the search is entered and returned without punctuation."
He added: "Whilst GeoPlace advises that punctuation should not be included in the data provided by local authorities, we will process data with punctuation where the council has officially named the street with punctuation."
A spokesman for Cambridgeshire Police said the force had not received any complaints of criminal damage relating to apostrophes being drawn on street signs.