# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(?:<FONT[^>]*>|<\\/FONT>)//gm;t' <<< "<UL><LI><FONT size=2 face=Verdana>random text<STRONG>random text</STRONG>random text<SPAN style=\"LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 11pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA\"><SPAN style=\"mso-spacerun: yes\"> </SPAN>random text</SPAN> </FONT></LI> <LI><FONT size=2 face=Verdana><FONT size=2 face=Verdana><STRONG>random text</STRONG></FONT></LI> <LI>random text</FONT></LI> <LI><FONT size=2 face=Verdana>random text</FONT></LI> <LI><FONT size=2 face=Verdana>random text</FONT></LI"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html