You can enter comments longer than 255 characters, you can also successfully submit edits with such comments and applying the edits will then fail because it can't fit the database field.

@400000004defdbd710ff016c Could not accept 14507759: Failed query:
@400000004defdbd710ff0554 'UPDATE artist SET country = ?, comment = ?, type = ? WHERE id = ?'
@400000004defdbd710ff093c (221 Folk collective Boat to Row, Captained by Michael King have cast off as a five piece, coupling a rare sense of genuine ease in each other's musical company with a fresh, energetic sound. Boat to Row have navigated the shores of the UK this past year, gracing stages at Dot-to-Dot, Truck, Wood, Moseley Folk and Gloucester Underground Festivals as well as supporting the likes of Willy Mason, The Acorn, Johnny Flynn and Slow Club with their warm sound. 2 604206)
@400000004defdbd710ff6314 DBD::Pg::st execute failed: ERROR: value too long for type character varying(255) at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 103.
@400000004defdbd710ff7a84
@400000004defdbd710ff7e6c at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 109
@400000004defdbd710ff8254 Sql::_ANON_('DBD::Pg::st execute failed: ERROR: value too long for type c...') called at /usr/local/share/perl/5.10.1/Try/Tiny.pm line 100
@400000004defdbd710ff863c Try::Tiny::try('CODE(0xcc77f90)', 'Try::Tiny::Catch=REF(0xe3c1128)') called at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 110
@400000004defdbd710ffa194 Sql::do('Sql=HASH(0xab36f30)', 'UPDATE artist SET country = ?, comment = ?, type = ? WHERE id...', 221, 'Folk collective Boat to Row, Captained by Michael King have c...', 2, 604206) called at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 166
@400000004defdbd710ffa964 Sql::update_row('Sql=HASH(0xab36f30)', 'artist', 'HASH(0x5c659c0)', 'HASH(0xcc786e0)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Data/Artist.pm line 200
@400000004defdbd710ffefb4 MusicBrainz::Server::Data::Artist::update('MusicBrainz::Server::Data::Artist=HASH(0xb034b78)', 604206, 'HASH(0x9cf2258)') called at /usr/local/lib/perl/5.10.1/Class/MOP/Method/Wrapped.pm line 54
@400000004defdbd710fff39c Class::MOP::Method::Wrapped::_ANON_('MusicBrainz::Server::Data::Artist=HASH(0xb034b78)', 604206, 'HASH(0x9cf2258)') called at /usr/local/lib/perl/5.10.1/Class/MOP/Method/Wrapped.pm line 89
@400000004defdbd711000724 MusicBrainz::Server::Data::Artist::update('MusicBrainz::Server::Data::Artist=HASH(0xb034b78)', 604206, 'HASH(0x9cf2258)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Edit/Generic/Edit.pm line 59
@400000004defdbd711001e94 MusicBrainz::Server::Edit::Generic::Edit::_ANON_('MusicBrainz::Server::Edit::Artist::Edit=HASH(0xe0a26b0)') called at /usr/local/lib/perl/5.10.1/Moose/Meta/Method/Overridden.pm line 36
@400000004defdbd71100227c MusicBrainz::Server::Edit::Generic::Edit::accept('MusicBrainz::Server::Edit::Artist::Edit=HASH(0xe0a26b0)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Data/Edit.pm line 533
@400000004defdbd711003604 eval

{...} called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Data/Edit.pm line 532
@400000004defdbd7110039ec MusicBrainz::Server::Data::Edit::_do_accept('MusicBrainz::Server::Data::Edit=HASH(0x9154450)', 'MusicBrainz::Server::Edit::Artist::Edit=HASH(0xe0a26b0)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Data/Edit.pm line 581
@400000004defdbd71100592c MusicBrainz::Server::Data::Edit::_ANON_('MusicBrainz::Server::Edit::Artist::Edit=HASH(0xe0a26b0)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Data/Edit.pm line 611
@400000004defdbd71100709c MusicBrainz::Server::Data::Edit::_close('MusicBrainz::Server::Data::Edit=HASH(0x9154450)', 'MusicBrainz::Server::Edit::Artist::Edit=HASH(0xe0a26b0)', 'CODE(0xe3b1230)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Data/Edit.pm line 581
@400000004defdbd711008424 MusicBrainz::Server::Data::Edit::accept('MusicBrainz::Server::Data::Edit=HASH(0x9154450)', 'MusicBrainz::Server::Edit::Artist::Edit=HASH(0xe0a26b0)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Data/Edit.pm line 524
@400000004defdbd7110097ac MusicBrainz::Server::Data::Edit::_ANON_() called at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 262
@400000004defdbd711009b94 Sql::_ANON_() called at /usr/local/share/perl/5.10.1/Try/Tiny.pm line 76
@400000004defdbd71100ab34 eval {...}

called at /usr/local/share/perl/5.10.1/Try/Tiny.pm line 67
@400000004defdbd71100af1c Try::Tiny::try('CODE(0xe371bf8)', 'Try::Tiny::Catch=REF(0xe0c3d68)') called at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 275
@400000004defdbd71100b304 Sql::_auto_transaction('CODE(0xe3b12a8)', 'Sql=HASH(0xab36f30)', 'Sql=HASH(0xc1c37f8)') called at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 287
@400000004defdbd71100ca74 Sql::_run_in_transaction_two('CODE(0xe3b12a8)', 'Sql=HASH(0xab36f30)', 'Sql=HASH(0xc1c37f8)') called at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 298
@400000004defdbd71100ce5c Sql::run_in_transaction('CODE(0xe3b12a8)', 'Sql=HASH(0xab36f30)', 'Sql=HASH(0xc1c37f8)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Data/Edit.pm line 525
@400000004defdbd71100e1e4 MusicBrainz::Server::Data::Edit::approve('MusicBrainz::Server::Data::Edit=HASH(0x9154450)', 'MusicBrainz::Server::Edit::Artist::Edit=HASH(0xe36ebf8)', 94387) called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Controller/Edit.pm line 108
@400000004defdbd71100e9b4 MusicBrainz::Server::Controller::Edit::approve('MusicBrainz::Server::Controller::Edit=HASH(0xa31c1f8)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 65
@400000004defdbd71101050c Catalyst::Action::execute('Catalyst::Action=HASH(0xa5ea390)', 'MusicBrainz::Server::Controller::Edit=HASH(0xa31c1f8)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
@400000004defdbd711011c7c eval

{...} called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
@400000004defdbd711012064 Catalyst::execute('MusicBrainz::Server=HASH(0xcdbff18)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xa5ea390)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/StackTrace.pm line 94
@400000004defdbd711013004 Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xcdbff18)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xa5ea390)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 60
@400000004defdbd7110137d4 Catalyst::Action::dispatch('Catalyst::Action=HASH(0xa5ea390)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst/ActionChain.pm line 39
@400000004defdbd711014774 Catalyst::ActionChain::dispatch('Catalyst::ActionChain=HASH(0xcd09bd0)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst/Controller.pm line 110
@400000004defdbd711015ee4 Catalyst::Controller::_ACTION('MusicBrainz::Server::Controller::Edit=HASH(0xa31c1f8)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 65
@400000004defdbd7110162cc Catalyst::Action::execute('Catalyst::Action=HASH(0xa5eb690)', 'MusicBrainz::Server::Controller::Edit=HASH(0xa31c1f8)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
@400000004defdbd71101820c eval {...}

called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
@400000004defdbd7110185f4 Catalyst::execute('MusicBrainz::Server=HASH(0xcdbff18)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xa5eb690)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/StackTrace.pm line 94
@400000004defdbd71101997c Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xcdbff18)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xa5eb690)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 60
@400000004defdbd71101a14c Catalyst::Action::dispatch('Catalyst::Action=HASH(0xa5eb690)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 257
@400000004defdbd71101b4d4 Catalyst::Dispatcher::_do_forward('Catalyst::Dispatcher=HASH(0x3ce9690)', 'forward', 'MusicBrainz::Server=HASH(0xcdbff18)', '_ACTION') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 237
@400000004defdbd71101bca4 Catalyst::Dispatcher::forward('Catalyst::Dispatcher=HASH(0x3ce9690)', 'MusicBrainz::Server=HASH(0xcdbff18)', '_ACTION') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 377
@400000004defdbd71101cc44 Catalyst::forward('MusicBrainz::Server=HASH(0xcdbff18)', '_ACTION') called at /usr/local/share/perl/5.10.1/Catalyst/Controller.pm line 84
@400000004defdbd71101d414 Catalyst::Controller::_DISPATCH('MusicBrainz::Server::Controller::Edit=HASH(0xa31c1f8)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 65
@400000004defdbd71101e3b4 Catalyst::Action::execute('Catalyst::Action=HASH(0xa5e2c10)', 'MusicBrainz::Server::Controller::Edit=HASH(0xa31c1f8)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
@400000004defdbd71101fb24 eval

{...} called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
@400000004defdbd71101ff0c Catalyst::execute('MusicBrainz::Server=HASH(0xcdbff18)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xa5e2c10)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/StackTrace.pm line 94
@400000004defdbd711021e4c Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xcdbff18)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xa5e2c10)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 60
@400000004defdbd71102261c Catalyst::Action::dispatch('Catalyst::Action=HASH(0xa5e2c10)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 257
@400000004defdbd7110235bc Catalyst::Dispatcher::_do_forward('Catalyst::Dispatcher=HASH(0x3ce9690)', 'forward', 'MusicBrainz::Server=HASH(0xcdbff18)', '/edit/_DISPATCH') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 237
@400000004defdbd711023d8c Catalyst::Dispatcher::forward('Catalyst::Dispatcher=HASH(0x3ce9690)', 'MusicBrainz::Server=HASH(0xcdbff18)', '/edit/_DISPATCH') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 377
@400000004defdbd711025114 Catalyst::forward('MusicBrainz::Server=HASH(0xcdbff18)', '/edit/_DISPATCH') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 105
@400000004defdbd7110258e4 Catalyst::Dispatcher::dispatch('Catalyst::Dispatcher=HASH(0x3ce9690)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1611
@400000004defdbd711026884 Catalyst::dispatch('MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/Static/Simple.pm line 76
@400000004defdbd711026c6c Class::MOP::Class:::around('CODE(0x3710270)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/lib/perl/5.10.1/Class/MOP/Method/Wrapped.pm line 159
@400000004defdbd711027ff4 Class::MOP::Method::Wrapped::_ANON_('MusicBrainz::Server=HASH(0xcdbff18)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server.pm line 251
@400000004defdbd7110283dc Class::MOP::Class:::around('CODE(0xa850a58)', 'MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/lib/perl/5.10.1/Class/MOP/Method/Wrapped.pm line 159
@400000004defdbd71102a31c Class::MOP::Method::Wrapped::_ANON_('MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/lib/perl/5.10.1/Class/MOP/Method/Wrapped.pm line 89
@400000004defdbd71102aaec MusicBrainz::Server::dispatch('MusicBrainz::Server=HASH(0xcdbff18)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1952
@400000004defdbd71102ba8c eval {...}

called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1943
@400000004defdbd71102be74 Catalyst::handle_request('MusicBrainz::Server', 'env', 'HASH(0x435bde0)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/AutoRestart.pm line 114
@400000004defdbd71102c644 Catalyst::Plugin::AutoRestart::handle_request('MusicBrainz::Server', 'env', 'HASH(0x435bde0)') called at /usr/local/share/perl/5.10.1/Catalyst/Engine/FastCGI.pm line 149
@400000004defdbd71102d5e4 Catalyst::Engine::FastCGI::run('Catalyst::Engine::FastCGI=HASH(0x43253a0)', 'MusicBrainz::Server', '127.0.0.1:55901', 'HASH(0x1f9dd48)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 2396
@400000004defdbd71102d9cc Catalyst::run('MusicBrainz::Server', '127.0.0.1:55901', 'HASH(0x1f9dd48)') called at ./script/musicbrainz_fastcgi.pl line 28
@400000004defdbd71102e96c at /home/musicbrainz/musicbrainz-server/script/../lib/Sql.pm line 262
@400000