special-use missing in 2.3 imap connection

[Marc]

Should I specify special_use any where, it is missing from my telnet imap.local 
143

2.2: * OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE 
SPECIAL-USE STARTTLS AUTH=PLAIN] Dovecot ready.

2.3: * OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE 
            STARTTLS AUTH=PLAIN] Dovecot ready.