Writing guidelines for UI copy

How many of these copy bugs have you seen before?

Don't

Click here to register.

Do

Register here.

"Click here" syndrome

We're no longer in the 90's, but some habits are hard to kick. I'm always surprised how often we ask users to "click here". I usually include something like this in writing guidelines:
Hyperlink descriptively: If it's a webpage, it matters for SEO.
Avoid saying "click here". It's old-fashioned and not device-agnostic.
Focus on the verb that gets to intention, in this case: Register.
Hyperlink the full action: This increases the surface area so users don't have to mouse/tap around to reach "here".
​If possible, make it a button.

Don't

View your invoice

Do

View my invoice

"Your" vs "my"

We're so used to representing ourselves that we often speak to users, forgetting that they are actually alone with a screen in that moment. When it comes to personal space, "my" almost always wins. Instead of telling someone what to do in their own home, we should reinforce their sense of ownership. Some guidelines:  
When in the user's space, reinforce their sense of ownership by writing in first-person – "my" instead of "your".
Don't mix pronouns in the same screen. 

Don't

Log into your myAccount.

Do

Log into your account.

"myAccount" syndrome

I like this example because I've encountered it so many times. Mixed pronouns, bizarre camel-case naming. You'd be surprised how often internal product terms make it into user-facing communications without adaptation. "myAccount" seems to be a common product name for web-based user account management. This tends to surface all over the place – in user-facing emails, webpages, in the app. I usually add the following in the writing guidelines: 
Don't mix pronouns.
Think from the user's perspective. Avoid internal terms that users may not understand.
Account – Refer simply to the user's account, never to "myAccount".

Don't

For more information, please contact Customer Support.

Do

Need help? Please contact us.

"Not me" syndrome

Usually an indication of silo-ed thinking. Of course, user-facing communications are handled in reality by many teams – Customer Support, Web, Social Media, CLM, UX, etc. But to users "we" are always just one company. Why refer to the "car2go blog" when it is simply "our blog"? Staying in character builds a more unified persona and narrative for the whole user experience. My guidelines:
Avoid referring to "the company" or other teams in third person. Simply take the first-person plural: "we", "our", "us". 

Don't

By charging our cars, you will earn 5 credits.

Do

Each time you charge a car, you earn 5 € of credit.

"Plural credit" syndrome

When it comes to if-then conditions, it's best to be crystal clear. The "before" version leaves open to interpretation the number of times users would have to charge a car to earn "credits". And how much is a credit worth anyway? In this case, users earn an actual euro amount – meaning "credits" isn't an actual unit. "Credits" tends to be misused in UI copy and spoken language all the time. I eventually had to add the following to the writing guidelines: 
Credit – Mass noun (like "debt"). Never pluralised. Not an actual unit. Always to be specified with the actual value in local currency, i.e. "€", "$", "£".

Don't

By clicking Cancel My Subscription, your subscription will be terminated by the current subscription period (23 May 2020) and you won't be charged afterwards anymore. ​

Do

Cancelling your subscription means your SHARE NOW Pass will no longer renew on 23 May 2020.

Legalese

Legal teams care about customers. You see how in the way they try to make the consequences of clicking a button so dramatically clear to users. But a little goes a long way. Here I shortened the sentence by focussing on the intention (no renewal on date) and removed the mixed pronoun in the button. I also included the product name and used "renewal" instead of "charged" to maintain the product narrative (i.e. a monthly pass that auto-renews).
Get to intention. Don't obfuscate meaning with too much information. 
Use glossary-defined terms and verbs to maintain a consistent narrative.

Don't

⚠️ Translations not available. Falling back to non-localized texts.

Do

⚠️ Pardon our French... We can't seem to load your preferred language right now.

"Translation" syndrome

Error messages! I'll spare you the run-of-the-mill "Please enter a valid 6-digit code" examples. I like to use this one as an example of internal thinking: Nobody thinks of their spoken language as a "translation". Since the character limit and tone-of-voice allowed for some humour, I allowed myself a bit of fun here. I also usually avoid idioms, but in this case the translators came up with some irresistible adaptations: 

DE: Das kommt uns Spanisch vor... 
​FR: L'appli vient de perdre son latin... 

Officially, my writing guidelines say: 
Avoid idioms. They're easy to misinterpret and can be difficult to translate.
Copy that.