diff --git a/compile/LoggerReporter.scala b/compile/LoggerReporter.scala
index 85db4ee44..9fd586d8a 100644
--- a/compile/LoggerReporter.scala
+++ b/compile/LoggerReporter.scala
@@ -115,7 +115,7 @@ class LoggerReporter(maximumErrors: Int, log: Logger) extends xsbti.Reporter
 	
 	def log(pos: Position, msg: String, severity: Severity): Unit =
 	{
-		allProblems += problem(pos, msg, severity)
+		allProblems += problem("", pos, msg, severity)
 		severity match
 		{
 			case Warn | Error =>
diff --git a/compile/inc/Compile.scala b/compile/inc/Compile.scala
index 6b3761ca0..2187ae740 100644
--- a/compile/inc/Compile.scala
+++ b/compile/inc/Compile.scala
@@ -63,11 +63,11 @@ private final class AnalysisCallback(internalMap: File => Option[File], external
 	private def add[A,B](map: Map[A,Set[B]], a: A, b: B): Unit =
 		map.getOrElseUpdate(a, new HashSet[B]) += b
 
-	def problem(pos: Position, msg: String, severity: Severity, reported: Boolean): Unit =
+	def problem(category: String, pos: Position, msg: String, severity: Severity, reported: Boolean): Unit =
 	{
 		for(source <- m2o(pos.sourceFile)) {
 			val map = if(reported) reporteds else unreporteds
-			map.getOrElseUpdate(source, ListBuffer.empty) += Logger.problem(pos, msg, severity)
+			map.getOrElseUpdate(source, ListBuffer.empty) += Logger.problem(category, pos, msg, severity)
 		}
 	}
 
diff --git a/compile/interface/CompilerInterface.scala b/compile/interface/CompilerInterface.scala
index 0c0488b72..c0110af5a 100644
--- a/compile/interface/CompilerInterface.scala
+++ b/compile/interface/CompilerInterface.scala
@@ -84,7 +84,7 @@ private final class CachedCompiler0(args: Array[String], initialLog: WeakLog) ex
 			} finally {
 				compiler.clear()
 			}
-			dreporter.problems foreach { p => callback.problem(p.position, p.message, p.severity, true) }
+			dreporter.problems foreach { p => callback.problem(p.category, p.position, p.message, p.severity, true) }
 		}
 		dreporter.printSummary()
 		if(!noErrors(dreporter)) handleErrors(dreporter, log)
@@ -96,10 +96,14 @@ private final class CachedCompiler0(args: Array[String], initialLog: WeakLog) ex
 	}
 	def processUnreportedWarnings(run: compiler.Run)
 	{
-			implicit def listToBoolean[T](l: List[T]): Boolean = error("source compatibility only, should never be called")
-			implicit def listToInt[T](l: List[T]): Int = error("source compatibility only, should never be called")
-		compiler.logUnreportedWarnings(run.deprecationWarnings)
-		compiler.logUnreportedWarnings(run.uncheckedWarnings)
+			// allConditionalWarnings and the ConditionalWarning class are only in 2.10+
+			final class CondWarnCompat(val what: String, val warnings: mutable.ListBuffer[(compiler.Position, String)])
+			implicit def compat(run: AnyRef): Compat = new Compat
+			final class Compat { def allConditionalWarnings = List[CondWarnCompat]() }
+
+		val warnings = run.allConditionalWarnings
+		if(!warnings.isEmpty)
+			compiler.logUnreportedWarnings(warnings.map(cw => ("" /*cw.what*/, cw.warnings.toList)))
 	}
 	object compiler extends CallbackGlobal(command.settings, dreporter)
 	{
@@ -149,13 +153,12 @@ private final class CachedCompiler0(args: Array[String], initialLog: WeakLog) ex
 			meth.setAccessible(true)
 			meth.invoke(this)
 		}
-		def logUnreportedWarnings(seq: List[(Position,String)]): Unit = // Scala 2.10.x and later
+		def logUnreportedWarnings(seq: Seq[(String, List[(Position,String)])]): Unit = // Scala 2.10.x and later
 		{
-			for( (pos, msg) <- seq) yield
-				callback.problem(reporter.asInstanceOf[DelegatingReporter].convert(pos), msg, Severity.Warn, false)
+			val drep = reporter.asInstanceOf[DelegatingReporter]
+			for( (what, warnings) <- seq; (pos, msg) <- warnings) yield
+				callback.problem(what, drep.convert(pos), msg, Severity.Warn, false)
 		}
-		def logUnreportedWarnings(count: Boolean): Unit = () // for source compatibility with Scala 2.8.x
-		def logUnreportedWarnings(count: Int): Unit = () // for source compatibility with Scala 2.9.x
 		
 		def set(callback: AnalysisCallback, dreporter: DelegatingReporter)
 		{
diff --git a/compile/persist/AnalysisFormats.scala b/compile/persist/AnalysisFormats.scala
index e1fec5237..6b6dc2798 100644
--- a/compile/persist/AnalysisFormats.scala
+++ b/compile/persist/AnalysisFormats.scala
@@ -53,7 +53,7 @@ object AnalysisFormats
 		wrap[SourceInfo, (Seq[Problem],Seq[Problem])](si => (si.reportedProblems, si.unreportedProblems), { case (a,b) => SourceInfos.makeInfo(a,b)})
 
 	implicit def problemFormat(implicit posF: Format[Position], msgF: Format[String], sevF: Format[Severity]): Format[Problem] =
-		asProduct3(problem _)( p => (p.position, p.message, p.severity))
+		asProduct4(problem _)( p => (p.category, p.position, p.message, p.severity))
 
 	implicit def positionFormat: Format[Position] =
 		asProduct7( position _ )( p => (m2o(p.line), p.lineContent, m2o(p.offset), m2o(p.pointer), m2o(p.pointerSpace), m2o(p.sourcePath), m2o(p.sourceFile)))
diff --git a/interface/src/main/java/xsbti/AnalysisCallback.java b/interface/src/main/java/xsbti/AnalysisCallback.java
index 2ba6f6c83..c23b43ecd 100644
--- a/interface/src/main/java/xsbti/AnalysisCallback.java
+++ b/interface/src/main/java/xsbti/AnalysisCallback.java
@@ -26,5 +26,5 @@ public interface AnalysisCallback
 	public void api(File sourceFile, xsbti.api.SourceAPI source);
 	/** Provides problems discovered during compilation.  These may be reported (logged) or unreported.
 	* Unreported problems are usually unreported because reporting was not enabled via a command line switch. */
-	public void problem(Position pos, String msg, Severity severity, boolean reported);
+	public void problem(String what, Position pos, String msg, Severity severity, boolean reported);
 }
\ No newline at end of file
diff --git a/interface/src/main/java/xsbti/Problem.java b/interface/src/main/java/xsbti/Problem.java
index cf2641900..db7f67b22 100644
--- a/interface/src/main/java/xsbti/Problem.java
+++ b/interface/src/main/java/xsbti/Problem.java
@@ -5,6 +5,7 @@ package xsbti;
 
 public interface Problem
 {
+	String category();
 	Severity severity();
 	String message();
 	Position position();
diff --git a/util/log/Logger.scala b/util/log/Logger.scala
index 1f6d4d3a5..7715b80db 100644
--- a/util/log/Logger.scala
+++ b/util/log/Logger.scala
@@ -79,9 +79,10 @@ object Logger
 			val sourceFile = o2m(sourceFile0)
 		}
 
-	def problem(pos: Position, msg: String, sev: Severity): Problem =
+	def problem(cat: String, pos: Position, msg: String, sev: Severity): Problem =
 		new Problem
 		{
+			val category = cat
 			val position = pos
 			val message = msg
 			val severity = sev