The　flaw　tips　in　brittle　rocks　are　often　the　sources　of　crack　initiation　and　growth　due　to　the　stress　concentration,　which　commonly　governs　the　rock　strength.　However,　a　unified　framework　identifying　the　compression-induced　crack　types,　ultimate　failure　patterns　and　the　cracking　levels　of　brittle　flawed　rocks　under　different　mechanical　confinements　is　not　yet　available.　This　study　conducts　the　laboratory　compression　experiments　with　the　AE　monitoring　to　explore　the　failure　characteristics　of　flawed　limestone　and　its　confinement-dependency.　Four　new　crack　types　including　loop　crack,　secondary　transverse　crack,　near-field　transverse　crack　and　far-field　transverse　crack　are　found　experimentally,　and　then　a　modified　crack　type　classification　strategy　is　proposed.　Four　failure　patterns　including　the　sigma(1)-axisymmetric　flaw-disturbed　spalling　for　uniaxial　compression,　the　sigma(3)-transverse-symmetric　flaw-disturbed　spalling　for　biaxial　compression,　the　sigma(1)　-axisymmetric　flaw-disturbed　shearing　for　conventional　triaxial　compression,　and　the　mixed　sigma(3)-transverse-symmetric　flaw-disturbed　shearing　and　sigma(2)-transverse-symmetric　flaw-disturbed　spalling　for　true　triaxial　compression,　are　documented　for　the　first　time.　Moreover,　an　acousto-mechanics-based　classification　methodology　of　rock　cracking　levels　is　established,　as　well　as　an　AF　(average　frequency)-RA　(rising　angle)-based　Kernel　density　estimation　method　for　interpreting　the　rock　cracking　nature　and　the　strength　mechanism.　This　paper　gets　insights　into　the　mechanical　confinement-dependency　of　the　rock　failure　characteristics　incorporating　the　pre-existing　flaws　and　help　interpret　the　field　observations.