Is it possible to Change the fieldset / tab names for a content type XML file? If not, what are the options ( I assume changing it in a po-file will change all other content types)
So, in the screenshot, I want to change 'Default' to 'Something' and 'Categorization' to 'Another'.
We did that at work, let me grab my laptop to see how we actually did it 
So, from a quick look at our code, it seems that the gist of it is:
from plone.dexterity.browser.add import DefaultAddForm
from plone.dexterity.browser.edit import DefaultEditForm
class ArticleAddForm(DefaultAddForm):
default_fieldset_label = _('Article')
class ArticleEditForm(DefaultEditForm):
default_fieldset_label = _('Article')
i.e. create a custom add/edit form for your content type and set the default_fieldset_label to your preferred name
only for the sake of completeness, the registration for the adapter:
<!-- Register AddForm for Collection -->
<adapter
factory=".views.CollectionAddFormView"
provides="zope.publisher.interfaces.browser.IBrowserPage"
for="Products.CMFCore.interfaces.IFolderish
mfd.eportal.interfaces.IMfdEportalLayer
plone.dexterity.interfaces.IDexterityFTI"
name="Collection"
/>
<!-- Override EditForm for Collection -->
<browser:page
name="edit"
for="plone.app.contenttypes.interfaces.ICollection"
class=".views.CollectionEditFormView"
permission="cmf.ModifyPortalContent"
layer="mfd.eportal.interfaces.IMfdEportalLayer"
/>
class CollectionAddForm(DefaultAddForm):
portal_type = "Collection"
default_fieldset_label = _('My Fieldset Label')
class CollectionEditForm(DefaultEditForm):
portal_type = "Collection"
default_fieldset_label = _('My Fieldset Label')
class CollectionAddFormView(DefaultAddView):
form = CollectionAddForm
class CollectionEditFormView(DefaultEditView):
form = CollectionEditForm
Another solution is to use a Diazo rule in your theme.
Additionally you could override the other group labels like this:
class ArticleAddForm(DefaultAddForm):
def update(self):
super().update()
for group in self.groups:
if group.id == "categorization":
group.label = _("My custom label")
I got an error on 'id', but this (using label) works:
class CollectionAddForm(DefaultAddForm):
def update(self):
super().update()
for group in self.groups:
if group.label == "Categorization":
group.label = "My
OK .. this was a wild guess 
looking at the plone.z3cform.fieldsets.group module it should be
group.__name__
instead of
group.id
This works, but I am courious about a few things and one remark.
It does seem like the important part in the adapter is the 'name', so I can change it to:
for="*
mfd.eportal.interfaces.IMfdEportalLayer
plone.dexterity.interfaces.IDexterityFTI"
name="Folder"
and it will work for 'Folders', it does not even look like I need the browser:page part
I also wonder, what is the line
portal_type = "Collection"
for ?
For the Add Form you need the Adapter, for the Edit Form you need the Browser Page.
The DefaultEditForm inherit from DexterityExtensibleForm and in this class the portal_type is needed.
Turns out I still have not solved the edit form (used * just to be sure), any idea?
<!-- Override EditForm for Action Items -->
<browser:page
name="edit"
for="*"
class=".views.ActionItemsEditFormView"
permission="cmf.ModifyPortalContent"
layer="Myaddon.ActionItems.interfaces.IMyaddonActionitemsLayer"
/>
and in edit view I have the same as in add
class ActionItemsEditForm(DefaultEditForm):
portal_type = "action_items"
default_fieldset_label = 'Home'
class ActionItemsEditFormView(DefaultEditView):
form = ActionItemsEditForm
I see that 'portal_type' is mentioned 'everywhere I look', but while making a content type TTW, I tried
<browser:page
name="edit"
for="Products.CMFCore.interfaces.IFolderish"
class=".views.ActionItemsEditFormView"
permission="cmf.ModifyPortalContent"
And used
portal_type = "my_content_type"
default_fieldset_label = 'My Label'
in the edit form
And 'My Label' show both for 'Folder' and for 'My content type'