If you use an HTML element output type, with the HTML tag as "li", then it will output a list (you'll have to supply the enclosing UL tags around the TV tags).
Or if you use a delimiter output type, specifying a comma, you'll get a comma-delimited list.
All the key-value method does is provide a different label for the checkboxes, while their values will be the second part. It just depends on what you want to do with the TV's content.
Here's what's saved in the database with just the values, no key-value:
Rooms with En Suite||Heated Indoor Swimming Pool||Sauna||Exercise Studio||Treatment Room||Outdoor Swimming Pool
And here's what's saved in the database with key->value input options:
So only the values are saves as a string using || as the default delimiter. The output options break down the string and process it according to the option chosen. Notice the one with the value of 0 isn't saved at all.
[ed. note: sottwell last edited this post 10 years, 9 months ago.]