When trying to enable encryption for certain columns in Designer | One Identity Manager Schema, the "Encrypted" check box field is grayed out and cannot be enabled:
In general, String and Text columns can be encrypted. However, storing encrypted values causes a storage overhead so Identity Manager (1IM) requires columns to hold at least 606 characters in order to enable encryption.
Columns shorter than this, e.g. PersonalTitle on table Person with 32 characters, cannot be encrypted with CryptoConfig so the option is disabled in Designer.
If there is a need to encrypt such information, the suggestion is to use a custom schema extension with sufficient length, as described above.