For the most part, all localisation is done within the phdcc.Data.Form module - see the Form editing page for full details.

Registering users:

After the user has been created and logged in, a registration email is sent to the user with a BCC to the form email address (if present). The email is formatted with the DNN localisation routines. By default, the email subject and body are taken from the EMAIL_USER_REGISTRATION_PUBLIC_SUBJECT and EMAIL_USER_REGISTRATION_PUBLIC_BODY resource names in \App_GlobalResources\GlobalResources.resx. You can use phdcc.Data specific alternatives using the resources in phdcc.Data.Form/App_LocalResources/ViewForm.ascx.resx or the localised equivalent. Specify non-blank values for the email subject and body from the PHDCC_FORM_EMAIL_USER_REGISTRATION_SUBJECT.Text and PHDCC_FORM_EMAIL_USER_REGISTRATION_BODY.Text resource names. The text is personalised, eg [User:DisplayName] is replaced with the user's display name.

If there is an error creating a user, DNN returns an error code. The error is then translated into a localised string, obtained from \App_GlobalResources\SharedResources.resx or the localised equivalent. This table shows the mapping between DNN error and the string used: