There are some types of document which require rigid
translation of the original, ommiting and adding nothing.
Legal texts belong to this group and patents. In such
cases the translator has the minimum of freedom.
Translators should correct grammatical mistakes, wrong
word choices and other linguistic defects in a badly
written source text.
They should also polish the translation of the texts
which include swearwords and take note of any
omission of dates or distortion of facts because it
is their moral and professional duty to translate
correct information.
Yet, translators shouldn't change the content of source
texts no matter how they feel about it.