krb5_principal_set_realm
krb5_principal_set_realm(context,server,my_realm);
ret = krb5_principal_set_realm(context, *out, sourcename->realm);
ret = krb5_principal_set_realm(context,
ret = krb5_principal_set_realm(context, referral.server, client_realm);
krb5_principal_set_realm (context, principal, client_realm);
ret = krb5_principal_set_realm(context,
krb5_principal_set_realm (
ret = krb5_principal_set_realm(context, principal, *r);