deny some values to be filtering

Hello
I would like to deny some values to be filtering, in a text field, is there a solution to do that please ?

Hello

only if you change edit field and change its type to:
'textselect'

NOTE1: a dropdown select of existing values will appear in item form
NOTE2: you can customize the drop down select to show only a few value


This is because customized selection of values for filtering is currently implemented only for:
"indexable fields":

select, selectmultiple,
textselect
radio, radioimage
checkbox, checkboximage

So after you change type
in the filtering TAB select to customize the filtering values

either select to show specific values
or select to use and SQL query that excludes values
(add your values in the NOT IN below)

Thank you for your usefull explanation !
I think I have all tried but I don't know how to do this : I would like to disable the possibility to display all items with a text field : it's possible to define a default value for the filter in global configuration and it's usefull, but is it possible to disable the possibility to delete this default-value in frontend and return an empty value instead (that diplay all items) ?

I would like to disable the possibility to display all items with a text field : it's possible to define a default value for the filter in global configuration and it's usefull, but is it possible to disable the possibility to delete this default-value in frontend and return an empty value instead (that diplay all items) ?

Hello i am not sure that i understand you

if you want to have a "locked" filter value then it is possible
besides parameter for "default" filter value there is a parameter for "locked" filter values

the above parameters exist
in component configuration
in each category configuration
and in "category-like" menu items

Hello, thank you for your answers, but what I'm looking for is not possible with filter-default-value (in component or category or menu-item) even if locked :
With a text field, it's possible to enter an empty filter value in frontend, that list all items. I just would like to disable this possiblity (to enter an empty value), but with the possiblity to enter all other values, is there a solution for this ?
(the textselect can do that but only with drop-down select-value filter)

did you test mask option in text field ?