Drive-by and closed.
Why one asks? It is an old rule. A link without substantial comment or summary, could be a link to spam site, or some unpleasant site with material not suited for our population. Sexual, racial, violent, political, or some other unpleasantness.
Thus, we discourage such. If you post a link, you need to give enough enough so that we know it is a meaningful contribution to the TFL discussion.
The staff does not have the responsibility to open every link to check it.
Thanks.