How an PHPBB forum administrator can allow members to embed Youtube videos into their posts/topics?

1. Login into PHPBB administration panel
2. CLick "POSTING" tab on the top
3. In the "BBCodes" section Add new BB code.

Examples field:
HTML replacement field:
<object width="640" height="360"><param name="movie" value="{IDENTIFIER}://{SIMPLETEXT}"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="{IDENTIFIER}://{SIMPLETEXT}" type="application/x-shockwave-flash" width="640" height="360" allowscriptaccess="always" allowfullscreen="true"></embed></object>
Help line field:
Embed Youtube video by pasting its full URL like

- This also allows Full screen video playback
- https and http URLs both works
- non www URL do NOT works