Greek characters in Custom Fields Label, Possible Bug?

When I create a Custom Field and give it a label using Greek characters, the result is a wrong column name ignoring all Greek characters
Settings > Custom Field > New
Table - User, Label ΣΣΣ (ΣΣΣ is Greek characters only)

The resulting column name is user_custom_

If you don’t notice the problem and try to create a new custom field in the same table, again using Greek characters only, you get the MySQL error

Duplicate column name 'user_custom_'
ALTER TABLE `ip_user_custom` ADD `user_custom_` VARCHAR(255) NOT NULL

The problem can be reproduced 100% of the time. The problem might be in effect with other non-latin sets.

As a workaround I create the custom field with a latin Label and then rename the label directly in the database.

Its not a bug but more like a security feature. The app replaces non-latin characters to prevent issues with the database and the displaying.