In this post:
the part after the line is between < small > and </ small >¹ and in the right side preview it is correctly presented. Instead, when browsed the small effect is not applied.
I know that you did not developed this forum framework, just pass-by the bug-report. 
notes
¹ spaces has been applied to show the tag and let it not be interpreted. Also this note are between the small tag but it does not show up smaller.