appdata validation and <li> too long

[Bruno Wolff III]

The hedgewars appdata file from upstream is getting flagged as invalid by 
rpmlint. I checked with appdata-validate and get the following:
appdata-validate -v /usr/share/appdata/hedgewars.appdata.xml
/usr/share/appdata/hedgewars.appdata.xml 1 problems detected:
• style-invalid         : <li> is too long

What is the limit on the size of list elements?
Does this really break anything or can I just leave it?