If I'm not wrong for that, are the templates.
Modify character style in your default template, and it will be used for every new document.
https://help.libreoffice.org/latest/en-US/text/shared/guide/standard_template.html?&DbPAR=WRITER&System=WIN

Please if you are not agreed reopen it.

When I open different documents, with own their different font sizes and font names, the character's style application doesn't adapt. I want a 'default' entry for font size, and font name.

If I had to save each new template, for each new document, then the character style editions wouldn't be much a difference.
A simple 'Default' parameter in saving the character style.

(In reply to cazlp from comment #2)
> When I open different documents, with own their different font sizes and
> font names, the character's style application doesn't adapt. I want a
> 'default' entry for font size, and font name.
> 
> If I had to save each new template, for each new document, then the
> character style editions wouldn't be much a difference.
> A simple 'Default' parameter in saving the character style.

Please read the link Miguel shared. You create a new default template with the character styles you like.

(In reply to Buovjaga from comment #3)
> (In reply to cazlp from comment #2)
> > When I open different documents, with own their different font sizes and
> > font names, the character's style application doesn't adapt. I want a
> > 'default' entry for font size, and font name.
> > 
> > If I had to save each new template, for each new document, then the
> > character style editions wouldn't be much a difference.
> > A simple 'Default' parameter in saving the character style.
> 
> Please read the link Miguel shared. You create a new default template with
> the character styles you like.

I had read it. And as stated before your reply, it didn't change the fact that each new document must be modified, and a 'default' size and name, in character styles, could improve a lot this software.

I'm talking about several different documents.
The link's solution, as already said, resolve as much as individually change them at each document.

(In reply to cazlp from comment #4)
> (In reply to Buovjaga from comment #3)
> > (In reply to cazlp from comment #2)
> > > When I open different documents, with own their different font sizes and
> > > font names, the character's style application doesn't adapt. I want a
> > > 'default' entry for font size, and font name.
> > > 
> > > If I had to save each new template, for each new document, then the
> > > character style editions wouldn't be much a difference.
> > > A simple 'Default' parameter in saving the character style.
> > 
> > Please read the link Miguel shared. You create a new default template with
> > the character styles you like.
> 
> I had read it. And as stated before your reply, it didn't change the fact
> that each new document must be modified, and a 'default' size and name, in
> character styles, could improve a lot this software.
> 
> I'm talking about several different documents.
> The link's solution, as already said, resolve as much as individually change
> them at each document.

What you say is not true. New documents do not have to be modified because they get the default styles that you defined in your default template.

(In reply to Buovjaga from comment #5)
> (In reply to cazlp from comment #4)
> > (In reply to Buovjaga from comment #3)
> > > (In reply to cazlp from comment #2)
> > > > When I open different documents, with own their different font sizes and
> > > > font names, the character's style application doesn't adapt. I want a
> > > > 'default' entry for font size, and font name.
> > > > 
> > > > If I had to save each new template, for each new document, then the
> > > > character style editions wouldn't be much a difference.
> > > > A simple 'Default' parameter in saving the character style.
> > > 
> > > Please read the link Miguel shared. You create a new default template with
> > > the character styles you like.
> > 
> > I had read it. And as stated before your reply, it didn't change the fact
> > that each new document must be modified, and a 'default' size and name, in
> > character styles, could improve a lot this software.
> > 
> > I'm talking about several different documents.
> > The link's solution, as already said, resolve as much as individually change
> > them at each document.
> 
> What you say is not true. New documents do not have to be modified because
> they get the default styles that you defined in your default template.

What you're replying makes no sense or responds to what I said.
If I have multiple documents, and apply character styles on them, the template default font size which defined the character style font size messes with the current documents own unique font size and font name.

Different documents, different reedition to adapt the font size.
I guess I'll wait for someone to certify if they're changing anything. My suggestion would have a blank space on character styles, so they become permanently adaptive no matter which font name or size it be.

Thanks.

I'm trying to understand the issue but so far I am agreeing with m.a.riosv and Buovjaga.

Maybe you should be using a Paragraph style instead?

Or maybe your request is already covered by one of these reports:
- Bug 153623 - [Character styles] Make more clear that the font used is from the paragraph style
- Bug 136433 - Font in character style should 'inherited' font/fontsize etc if it's defined by paragraph style (instead of showing a 'random' font/font size)
- Bug 115311 - UI missing for nesting character styles