I like this Stack Overflow feature: when adding a comment to an answer or question, you have to type at least 15 characters. This discourages users to write meaningless comments à la ‘Nice!’ or ‘Awesome!’ and probably makes them more often use the features that were made for this (like up- or down-voting).

I like this Stack Overflow feature: when adding a comment to an answer or question, you have to type at least 15 characters.
This discourages users to write meaningless comments à la ‘Nice!’ or ‘Awesome!’ and probably makes them more often use the features that were made for this (like up- or down-voting).

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