Specsavers's application to trademark the term "should've" has been approved by the UK Intellectual Property Office (IPO).

The ruling now means that rival opticians and similar companies will not be able to use the word "should've" - or "shouldve" for those who are grammatically illiterate - in their marketing.

It is very rare that a company is able to trademark such a common word, given how frequently it is used in everyday life. However, there is a precedent. In 1993, Carlsberg trademarked 'probably'.

The thinking behind approving an application of this sort is that the word has become so synonymous with a brand that any use, in the context of its industry, would suggest an association with the company.

Famed from its "Should've gone to Specsavers" adverts, it is reasonable to think that if another company or product in the optical industry used the term 'term' in its marketing, it would relate to Specsavers.

Similarly, if you saw an advert for a new beer brand containing the phrase 'probably', you'd probably think it had some sort of association with Carlsberg.

Trademark lawyer Tania Clark, from Withers and Rogers, was surprised by the ruling. She said: "It is surprising that the office has accepted this trade mark for a single word, which is a verb in common usage.

It means that the retailer could soon have the right to exclude others from using the word 'should've' or 'shouldve' when communicating about certain classes of goods, including optician services, medical hearing aids and eyewear."