OCR suspect corrections not found in search

Question

I created a PDF from a scanned document. I ran the OCR inside Acrobat with Searchable Image. The OCR went fine, except with some mistakes for some of the words. I corrected those words by going through the suspects. I edited the wrongly guessed words and completed the check on all the suspects in Acrobat.
However, I cannot search those words that I have edited. When I copy the edited words and paste them in Notepad, I realise that the characters I had edited are showing up as square characters like this: he    o
As the characters I inserted into the document when correcting the suspects are turned into square characters, Acrobat couldn't recognise them and therefore cannot find them when I search for the actual word.
In my case, the word "hello" was mistakenly read as "he11o". So I changed the "11" to "ll" on the invisible layer of text through the "Find Suspect". But it turns out that they became square characters when I highlighted and copied the word with the selection tool.
How can I make sure that the corrections I make for OCR in Acrobat X will remain searchable?
PS: It seems like the square characters show up as empty spaces when I paste them on this forum.

Answer 1

Ok. But i don't get what h.264 is. I mean, is it a particular video format which is used by only a small number if videos?