Scientists and engineers, who perform complex calculations and comprehend incredible phenomena, usually feel that it's not enough to use ordinary round, curly or angle brackets. That's why they have a wider repertoire of symbols, which includes tortoise shell brackets. These originally-shaped signs tend to be paired up, and here we deal with the left bracket, which is considered to be the opening one.

If you are far from physics or mathematics, use the left tortoise shell bracket for text decoration. For example, instead of the simple round bracket, take this one and apply a unique font. Together with the opening sign, a similar closing one is put – [U:2773].