This was discussed some time ago. K Kruger adds his insights.
see: Basic Elements of Rub by Steve Petrone
(not sure how to add link perhaps someone could help)
I couldn't find the reference where I read it and then forgot to note that Kevin had said it. Mea culpa.
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Steve, go to the page that has the post you are referencing (ie Basic Elements). In the top "address" bar, tap it once to hilight the address--it starts
tvwbb.com/etc
Then hold your finger on the hilighted address till a window pops up. It'll give you options like select all and copy . Lift your finger (the addy will still be highlighted). Touch "copy".
Now, go to your new post, type what you want to say and add a couple of blank spaces. Then, touch and hold your finger in the blank area. Another bubble will pop up asking the same "cut copy or paste" question.
Touch "paste" and that link you copied from the source will paste into the blank area (it'll be highlighted as a link--different colour--once the new post is posted). Make sure there is only a blank space before the link starts and after it ends. Otherwise, it'll either not be "active" or it won't take you where you want to go when touched. Then submit your post.
Once it's "permanent" (posted), test the link by clicking on it. If it takes you where you want, you're done.