Meaning of warning message

[Hubs61]

What does this warning message mean ? Also, can it cause a conflict with the game ?

	Load mod: gaz53_milk_water Warning: Missing l10n for button BEL3LEFT in gaz53_milk_water Warning: Missing l10n for button BEL3RIGHT in gaz53_milk_water

[Heizer]

It says that the mod "gaz53_milk_water" is missing localization entries (l10n) for the function turnlight left and right.
If you check your key bindings in the options you will see that there will be a similar error in the list for these two entries. The error doesn't have any impact on the gameplay/functionality, it's just the missing translation/text for the input binding menu.
To fix this you have to add "BEL3LEFT" and "BEL3RIGHT" to the l10n section of your mods modDesc.xml.
You can find a good explanation right here: http://fs-uk.com/forum/index.php?topic=116543.0