ok, thanks a lot for your answer,
Assuming that the Module “Accounts” has a lot of relationships with other Modules, I could create these Files as example:
./custom/Extension/modules/Accounts/Ext/Language/en_GB.lang.php
./custom/Extension/modules/Cases/Ext/Language/en_GB.lang.php
./custom/Extension/modules/Contacts/Ext/Language/en_GB.lang.php
./custom/Extension/modules/Leads/Ext/Language/en_GB.lang.php
./custom/Extension/modules/Opportunities/Ext/Language/en_GB.lang.php
/… and so on for all Modules…
and after that I will write inside the en_GB.lang.php these values as example:
Is this fine?