Which famous dictionary publisher uses a 'diacritic mark' in their logo that actually serves as a clever visual pun related to their business?

In the intersection of linguistics and marketing, brand logos often incorporate sophisticated language principles to communicate with consumers. From phonetic symbolism to visual rhetoric, the most successful companies leverage linguistic knowledge to create memorable brand identities. This trivia question explores how one famous dictionary brand used language principles in their visual branding strategy.

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Merriam-Webster (with a small caret symbol that resembles both a pronunciation mark and suggests 'looking up' words)
Oxford Dictionaries (with a circumflex that forms an open book shape)
Collins (with a tilde that represents language flow and evolution)
Cambridge Dictionary (with an acute accent that points to knowledge acquisition)