In order to answer that question, we need to know the definition of “What’s a typographical error?”
During my experience doing mechanical QA I found out that some typographical errors are often mistakes that occur during the process of copying and pasting the final translation into a template, like an English template in Quark or InDesign.
As you paste the translation into the English template, you may leave behind some English words. In the case of Roman languages it’s more difficult to catch this error, while in languages like Korean, Chinese, Arabic or Hebrew the error is easier to identify.
See examples below:
Example #1: An easy case of identifying a typographical error
In English: Storage and Handling: Control must be stored upright, tightly sealed, at Room Temperature (20-25°C).
Incorrect Korean: S보관 및 취급: 대조 용액은 실온(20-25°C)에서 똑바로 세운 상태로 밀봉하여 보관해야 합니다.
“S” is a typographical error.
In English: Do not use if the package is open or damaged.
Incorrect Portuguese: Do Nunca utilizar ar ou qualquer meio gasoso para encher o balão.
“Do” is a typographical error.
How typographical errors affect the quality of the translation may differ based on the kind of typographical error.
While typographical errors represent poor quality of your translated document it may not affect the meaning of the translation; however, need to avoid having typographical errors in the translated documents.