
Take the expression outside of, for instance. In written English, the added and unnecessary preposition on the end (of) carries over from spoken English. While such a construction may find acceptability in spoken English, that preposition dangling on the end creates a redundancy which reduces the effectiveness of professional technical writing.
Since redundant words typically create less effective writing, experienced writers will take care to remove those extra words from their writing. Thus, the example sentence in the graphic above should be modified.
However it may be used, keep outside of out of your writing. At best the expression is simply redundant. At worst it communicates your message less effectively. And a less effective presentation reflects poorly on you, your organization, and your brand. So always take the high road and keep outside of out of your writing.