https://bugzilla.mozilla.org/show_bug.cgi?id=404309
404309 - [FIX]Colgroup span changes have no effect
RESOLVED (bzbarsky) in Core - Layout: Tables. Last updated 2008-02-14.
fixcolgroupspanchangeseffect
https://www.w3schools.com/TAGS/att_colgroup_span.asp
HTML colgroup span Attribute
Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, Python, PHP, Bootstrap, Java, XML...
htmlcolgroupspanattribute
https://apache.github.io/systemds/api/java/org/apache/sysds/runtime/compress/colgroup/class-use/ColGroupSDCSingle.html
Uses of Class org.apache.sysds.runtime.compress.colgroup.ColGroupSDCSingle (Apache SystemDS...
usesclassapache
https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/colgroup
colgroup HTML table column group element - HTML | MDN
html tablecolgroupcolumnelementmdn