[pipcat]

As surquizu remarked to me, with this new patch to allow searches on extra dictionaries, we can install many custom dictionaries and there is no need to replace existing ones. We can also make a copy of French and Dutch dictionaries as "Extra", so license issue will not apply and search will be allowed.

1- Apply patch to libnickel.so.1.0.0

Spoiler:

<Patch>
patch_name = `Allow searches on Extra dictionaries`
patch_enable = `yes`
#
# To allow searches on Extra dictionaries change space character at end of "Extra: " to another char (ex: "Extra:_")
# The space char causes a non-desired "English - English" when searching on Extra dictionary from main menu.
#
#replace_bytes = BA9478, 20, 5F
#
find_base_address = `\0E\0x\0t\0r\0a\0:\0\x20`
replace_string = 000d, `\x20`, `_`
</Patch>

2- We need a two chars code for each dictionary. If language doesn't exists on Kobo we can use its ISO-639-1 (Ex: Catalan => ca), otherwise we will assign a new fictitious code (Ex: English => e2, e3. French => f2).

3- Edit \.kobo\KoboKobo eReader.conf and fill ExtraLocales
ExtraLocales=ca, e2, e3, f2

4- Copy dictionary files to \.kobo\dict
dicthtml-ca.zip, dicthtml-e2.zip, dicthtml-e3.zip, dicthtml-f2.zip

5- Open db \.kobo\KoboReader.sqlite and insert rows on Dictionary table
-ca Català
-e2 English second dictionary
-e3 English third
-f2 Français bis