# Specify requirements and constraints

<br />

Help users understand requirements and constraints. Be specific.
Don't assume that users know the limitations of your system.

Not recommended
> The combined size of the attachments is too big.

Recommended
> The combined size of the attachments (14MB) exceeds the allowed limit (10MB). *\[Details about possible solution.\]*

*** ** * ** ***

Not recommended
> Permission denied.

Recommended
> Permission denied. Only users in \<group name\> have access. *\[Details about adding users to the group.\]*

*** ** * ** ***

Not recommended
> Time-out period exceeded.

Recommended
> Time-out period (30s) exceeded. *\[Details about possible solution.\]*

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**Next unit:** [Explain how to fix the problem](https://developers.google.com/tech-writing/error-messages/show-fix)