The set of special symbols contains mainly mathematical signs. Such as infinity sign, fractions, operators. There are also Greek letters, a copyright sign, currency signs and a trademark sign. Well, special and also random symbols, of course, too.
The mathematician Wallis was the first, who defined in 1655 the infinity sign like this symbol – ∞. Then he did not explain why he chose this sign. Perhaps this was due to the Roman number 1000 (originally looked like ↀ, or CƆ) or the last letter of the Greek alphabet – omega ω. The sign itself is more ancient. It is associated with Ouroboros, a snake that bites its tail.
Copyright © is a sign of copyright protection, is a Latin letter “c” (the first letter of the word «copyright»), located in a circle.
Mathematical signs – how to live without them? Subtract and divide. And neither more > nor less <.
And this is a very eco-friendly and very special symbol of universal recycling ♲. This Möbius strip with arrows is placed on the packaging of recycled materials.
? – a question mark is placed at the end of the sentence to indicate a question. It was found in print in the 16th century, however, it did not always expressed question. The image of the question mark is associated with the Latin word «quaestio» — which means finding the answer. The letter Q was written above O. With time this symbol mutated into what it is now. In Unicode you can find the inverted question mark ¿, as well as the reverse ⸮ and double one – ⁇.