% APNIC found the following authoritative answer from: whois.ripe.net

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://apps.db.ripe.net/docs/HTML-Terms-And-Conditions

% Note: this output has been filtered.
%       To receive output for a database update, use the "-B" flag.

% Information related to '146.133.224.0 - 146.133.255.255'

% Abuse contact for '146.133.224.0 - 146.133.255.255' is 'infofibra@enel.com'

inetnum:        146.133.224.0 - 146.133.255.255
netname:        ENEL-NET
descr:          ENEL S.p.A.
country:        IT
admin-c:        SR1588-RIPE
tech-c:         EL1045-RIPE
tech-c:         FS613-RIPE
tech-c:         FC94-RIPE
status:         LEGACY
mnt-by:         ENEL-LIR
created:        1970-01-01T00:00:00Z
last-modified:  2019-12-04T13:10:07Z
source:         RIPE

role:           ENEL LIR
address:        Enel Servizi S.r.l.
address:        V.le Italia, 26
address:        20099 Sesto San Giovanni (MI)
address:        Italia
remarks:        Internet site http://www.enel.it
admin-c:        MP24673-RIPE
tech-c:         SF1341-RIPE
tech-c:         VV500-RIPE
tech-c:         GG1185-RIPE
tech-c:         MI5426-RIPE
tech-c:         AB27321-RIPE
nic-hdl:        EL1045-RIPE
mnt-by:         ENEL-LIR
created:        2002-05-15T14:27:30Z
last-modified:  2023-04-18T13:54:46Z
source:         RIPE # Filtered

person:         Fabrizio Cavalieri
address:        H3G S.p.A.
address:        Via Alessandro Severo 246
address:        I-00145 Rome
address:        Italy
phone:          +39 06 59551
nic-hdl:        FC94-RIPE
created:        2001-11-23T12:24:39Z
last-modified:  2016-04-05T23:22:07Z
mnt-by:         RIPE-NCC-LOCKED-MNT
source:         RIPE # Filtered

person:         Fabrizio Sarcinelli
address:        ENEL spa
address:        Servizi Sistemi Informativi
address:        Via G.B. Martini, 3
address:        I-00198 Roma (RM)
address:        Italy
phone:          +39 6 85097516
fax-no:         +39 6 85097516
nic-hdl:        FS613-RIPE
created:        1970-01-01T00:00:00Z
last-modified:  2016-04-05T15:17:20Z
mnt-by:         RIPE-NCC-LOCKED-MNT
source:         RIPE

person:         Stefano Regaglia
address:        Enel.it S.p.A.
address:        V.le Italia, 26
address:        I-20099 Sesto S. Giovanni (MI)
address:        Italy
phone:          +39 02 7224 7714
fax-no:         +39 02 24989101
nic-hdl:        SR1588-RIPE
mnt-by:         ENEL-LIR
created:        1970-01-01T00:00:00Z
last-modified:  2003-02-06T09:56:04Z
source:         RIPE # Filtered

% Information related to '146.133.224.0/19AS12551'

route:          146.133.224.0/19
descr:          Enel.it
origin:         AS12551
mnt-by:         ENEL-LIR
created:        2004-06-09T11:53:00Z
last-modified:  2004-06-09T11:53:00Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.111 (ABERDEEN)

Search for
IP address lookups			Miscellaneous queries
-l	1st level less specific		-i	Inverse attributes	None admin-c admin-c,tech-c,zone-c author cross-mnt cross-nfy local-as mbrs-by-ref member-of mnt-by mnt-lower mnt-nfy mnt-routes notify nserver origin person referral-by rev-srv sub-dom tech-c upd-to zone-c
-L	All less specific		-T	Object types	All as-block as-set aut-num domain filter-set inet-rtr inet6num inetnum irt key-cert mntner peering-set person role route route-set rtr-set
-m	1st level more specific
-M	All more specific		Query hints Include "AS" in front of an AS number. Example: AS4808 Include "-t" (template only) or "-v" (template and description) in front of an object name to view the template Example: -t inetnum
-x	Exact match only
-d	Associated reverse domain