removing the param I think is the wrong direction. The whole purpose was to give the user flexibility in sizing the module. Now you've not only removed that ability but forced them into a fixed state. i.e. we're back into 1.5 days.

Please read all the comments @N6REJ

@N6REJ The page structure has absolutely no association with Bootstrap. We do NOT use Bootstrap column classes anymore for Cassiopeia. We are utilising CSS Grid which may be a "1.5 days" approach to you, but a 2017 approach to all UI developers

@C-Lodder you state that put yet you put the column class in!

<div class="col-md-6">
    <div class="myclass"></div>
</div>

I can only go by what you say/show/do.
While the name / function needs to be changed, the PURPOSE of it is valid.
grid does have column size & number ability just like bs does with col- so why not provide that ability EASILY.

The UI options are inherently limited without templates putting in their own parameters. Do we offer params mapping to just col-X or do we offer params for col-sm-X, col-md-X, col-lg-X, and col-xl-X as well? What if the UI framework used by the template doesn't use a markup driven grid like Bootstraps? What if its breakpoints don't align with those of Bootstrap (in terms of number and resolution)?

Long and short, the only reliable way to offer these sizing parameters is to continue to use HTML driven grids. Those have issues and limitations that are addressed by the newer CSS Grid implementations and it has been elected to focus on adapting our technology toward newer and preferred trends, not sticking to inherently broken and limited options.

@N6REJ - The backend and frontend templates are 2 completely different things. In the FE template we're using CSS grid for the page structure, whereas in Atum we're still using BS4.

you state that put yet you put the column class in!

As you can see by my actual code changes, I do not use col-md-6 in the Cassiopeia modChrome and clearly state in my comment above that I'm referring to Cassiopeia, not Atum.

@C-Lodder can you please give Test Instructions in your first Comment so Tester are sure where to look?

@mbabker I see what you mean. Is there anyway to allow the flexibility of module size param and non-rigid classes also without resorting to forcing the users to create css sizing?

Franz, this is only to remove a parameter. Just a code revoew will do

Is there anyway to allow the flexibility of module size param and non-rigid classes also without resorting to forcing the users to create css sizing?

Templates use the existing plugin events to extend the module edit form then use their extended parameters in the module chrome. An option that has always existed so that there isn't a reliance on trying to map a select list offering a mapping to BS2 spanX classes to an inflexible grid system.

Remove here:
https://github.com/C-Lodder/joomla-cms/blob/5d80ce9a7edb64b5582a50076365854eaa3a690c/administrator/templates/system/html/modules.php#L54

@mbabker

Templates use the existing plugin events to extend the module edit form then use their extended parameters in the module chrome

Anywhere explaining the details / how's of that anywhere?

@Quy done

@wilsonge merge?

@wilsonge @brianteeman are we removing the Bootstrap size parameter in modules? With the use of CSS Grid make no sense to keep a setting that is bootstrap related.