I'm assuming an empty value means it needs uploading. So you can just use an IF_EMPTY directive on the value.

{+START,IF_EMPTY,{$GET,some_value}}Show something to indicate it needs uploaded{+END}
{+START,IF_NON_EMPTY,{$GET,some_value}}This video exists on Facebook{+END}

I have it working on the gallery videos already, with the ($SET} in the video descriptions and the {$GET} in the templates, because custom catalogue fields are impossible to reference. I am referencing alternative sources other than YouTube and I can see them when viewing the actual video. That bit is done.

I was wondering if there was a way to output the Facebook videos with an empty {$GET,FACEBOOK_ID) on a Comcode page (in a list) using these values somehow, Not sure if it's possible to dp that, not sure if these values are global. Maybe they are limited to the scope they exist in. Maybe a Symbol would do it. I have no clue, hence asking if it's possible to make an advanced use of these Tempcode variables, if so, I think that would useful to tutorialise.

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