Java, discover all available flags with PrintFlagsFinal

not many people know that you can get the list of all supported JVM flags with -XX:+PrintFlagsFinal
example:
java -XX:+PrintFlagsFinal -version | grep -i gc
will print:

    uintx AdaptiveSizeMajorGCDecayTimeScale         = 10              {product}
    uintx AutoGCSelectPauseMillis                   = 5000            {product}
     bool BindGCTaskThreadsToCPUs                   = false           {product}
    uintx CMSFullGCsBeforeCompaction                = 0               {product}
    uintx ConcGCThreads                             = 0               {product}
     bool DisableExplicitGC                         = false           {product}
     bool ExplicitGCInvokesConcurrent               = false           {product}
     bool ExplicitGCInvokesConcurrentAndUnloadsClasses  = false           {product}
    uintx GCDrainStackTargetSize                    = 64              {product}
    uintx GCHeapFreeLimit                           = 2               {product}
    uintx GCLockerEdenExpansionPercent              = 5               {product}
     bool GCLockerInvokesConcurrent                 = false           {product}
     bool GCOverheadReporting                       = false           {product}
     intx GCOverheadReportingPeriodMS               = 100             {product}
    uintx GCPauseIntervalMillis                     = 0               {product}
    uintx GCTaskTimeStampEntries                    = 200             {product}
    uintx GCTimeLimit                               = 98              {product}
    uintx GCTimeRatio                               = 99              {product}
     bool HeapDumpAfterFullGC                       = false           {manageable}
     bool HeapDumpBeforeFullGC                      = false           {manageable}
    uintx MaxGCMinorPauseMillis                     = 18446744073709551615{product}
    uintx MaxGCPauseMillis                          = 18446744073709551615{product}
     bool OptimizeStringConcat                      = false           {C2 product}
     intx ParGCArrayScanChunk                       = 50              {product}
    uintx ParGCDesiredObjsFromOverflowList          = 20              {product}
     bool ParGCTrimOverflow                         = true            {product}
     bool ParGCUseLocalOverflow                     = false           {product}
     intx ParallelGCBufferWastePct                  = 10              {product}
     bool ParallelGCRetainPLAB                      = true            {product}
    uintx ParallelGCThreads                        := 10              {product}
     bool ParallelGCVerbose                         = false           {product}
     intx PerfMaxStringConstLength                  = 1024            {product}
     bool PrintClassHistogramAfterFullGC            = false           {manageable}
     bool PrintClassHistogramBeforeFullGC           = false           {manageable}
     bool PrintGC                                   = false           {manageable}
     bool PrintGCApplicationConcurrentTime          = false           {product}
     bool PrintGCApplicationStoppedTime             = false           {product}
     bool PrintGCDateStamps                         = false           {manageable}
     bool PrintGCDetails                            = false           {manageable}
     bool PrintGCTaskTimeStamps                     = false           {product}
     bool PrintGCTimeStamps                         = false           {manageable}
     bool PrintHeapAtGC                             = false           {product rw}
     bool PrintHeapAtGCExtended                     = false           {product rw}
     bool PrintJNIGCStalls                          = false           {product}
     bool PrintParallelOldGCPhaseTimes              = false           {product}
     bool PrintReferenceGC                          = false           {product}
     intx QueuedAllocationWarningCount              = 0               {product}
     bool ScavengeBeforeFullGC                      = true            {product}
     bool SpecialStringCompareToCC                  = true            {product}
     bool SpecialStringCompress                     = true            {product}
     bool TraceParallelOldGCTasks                   = false           {product}
     bool UseAdaptiveGCBoundary                     = false           {product}
     bool UseAdaptiveSizeDecayMajorGCCost           = true            {product}
     bool UseAdaptiveSizePolicyWithSystemGC         = false           {product}
     bool UseAutoGCSelectPolicy                     = false           {product}
     bool UseConcMarkSweepGC                        = false           {product}
     bool UseG1GC                                   = false           {product}
     bool UseGCOverheadLimit                        = true            {product}
     bool UseGCTaskAffinity                         = false           {product}
     bool UseMaximumCompactionOnSystemGC            = true            {product}
     bool UseParNewGC                               = false           {product}
     bool UseParallelGC                            := true            {product}
     bool UseParallelOldGC                          = false           {product}
     bool UseParallelOldGCCompacting                = true            {product}
     bool UseParallelOldGCDensePrefix               = true            {product}
     bool UseSerialGC                               = false           {product}
     bool UseStringCache                            = false           {product}