diff --git a/Minebot/src/net/famzangl/minecraft/minebot/ai/command/AICommandParameter.java b/Minebot/src/net/famzangl/minecraft/minebot/ai/command/AICommandParameter.java
index 1bee18c8..9f3e96b6 100644
--- a/Minebot/src/net/famzangl/minecraft/minebot/ai/command/AICommandParameter.java
+++ b/Minebot/src/net/famzangl/minecraft/minebot/ai/command/AICommandParameter.java
@@ -21,6 +21,9 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import net.famzangl.minecraft.minebot.ai.path.world.BlockSet;
+import net.minecraft.init.Blocks;
+
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.PARAMETER)
 public @interface AICommandParameter {
@@ -40,6 +43,15 @@ public boolean matches(BlockWithDataOrDontcare b) {
 		}
 	}
 	
+	public static class SurvivalBlockFilter extends BlockFilter {
+		private static final BlockSet NON_SURVIVAL_BLOCKS = new BlockSet(Blocks.air, Blocks.command_block);
+
+		@Override
+		public boolean matches(BlockWithDataOrDontcare b) {
+			return !NON_SURVIVAL_BLOCKS.contains(b);
+		}
+	}
+	
 	ParameterType type();
 
 	String description();
@@ -48,7 +60,7 @@ public boolean matches(BlockWithDataOrDontcare b) {
 	
 	boolean optional() default false;
 
-	Class<? extends BlockFilter> blockFilter() default AnyBlockFilter.class;
+	Class<? extends BlockFilter> blockFilter() default SurvivalBlockFilter.class;
 
 	String relativeToSettingsFile() default "";
 }
diff --git a/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockNameBuilder.java b/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockNameBuilder.java
index 6db3ccba..1176bb2c 100644
--- a/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockNameBuilder.java
+++ b/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockNameBuilder.java
@@ -22,6 +22,7 @@
 import net.famzangl.minecraft.minebot.ai.AIHelper;
 import net.famzangl.minecraft.minebot.ai.command.AICommandParameter.AnyBlockFilter;
 import net.famzangl.minecraft.minebot.ai.command.AICommandParameter.BlockFilter;
+import net.famzangl.minecraft.minebot.ai.command.BlockWithDataOrDontcare.IllegalBlockNameException;
 import net.minecraft.util.ResourceLocation;
 
 public class BlockNameBuilder extends ParameterBuilder {
@@ -53,14 +54,26 @@ public BlockArgumentDefinition(String description,
 
 		@Override
 		public boolean couldEvaluateAgainst(String string) {
-			BlockWithDataOrDontcare block = BlockWithDataOrDontcare.getFromString(string);
-			return block != null && blockFilter.matches(block);
+			try {
+				BlockWithDataOrDontcare block = BlockWithDataOrDontcare.getFromString(string);
+				return blockFilter.matches(block);
+			} catch (IllegalBlockNameException e) {
+				return false;
+			}
 		}
 
 		@Override
 		public void getTabCompleteOptions(String currentStart,
 				Collection<String> addTo) {
 			super.getTabCompleteOptions(currentStart, addTo);
+			
+			for (String s : BlockWithDataOrDontcare.getAllStrings()) {
+				String noPrefix = s.replaceFirst("^minecraft:", "");
+				if (s.startsWith(currentStart) || noPrefix.startsWith(currentStart)) {
+					addTo.add(noPrefix);
+				}
+			}
+			
 //			@SuppressWarnings("unchecked")
 			// BIG TODO: Get a list of all blocks for tab complete.
 //			final Set<ResourceLocation> keys = Block.blockRegistry.getKeys();
diff --git a/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockWithData.java b/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockWithData.java
index 710966b3..c307cad7 100644
--- a/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockWithData.java
+++ b/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockWithData.java
@@ -113,7 +113,7 @@ public String toBlockString() {
 		return getBlockString() + ":" + getMetaString();
 	}
 
-	private String getMetaString() {
+	protected String getMetaString() {
 		int value = getMetaValue();
 		int blockId = getBlockId();
 		for (NicerMetaValue n : nicerMeta) {
diff --git a/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockWithDataOrDontcare.java b/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockWithDataOrDontcare.java
index da7781f6..7e35bf2b 100644
--- a/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockWithDataOrDontcare.java
+++ b/Minebot/src/net/famzangl/minecraft/minebot/ai/command/BlockWithDataOrDontcare.java
@@ -1,40 +1,90 @@
 package net.famzangl.minecraft.minebot.ai.command;
 
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import net.famzangl.minecraft.minebot.ai.path.world.BlockSet;
 import net.famzangl.minecraft.minebot.ai.task.inventory.ItemWithSubtype;
 import net.minecraft.block.Block;
+import net.minecraft.block.state.IBlockState;
+import net.minecraft.init.Blocks;
 import net.minecraft.util.ResourceLocation;
 
 public abstract class BlockWithDataOrDontcare {
 
+	public static class IllegalBlockNameException extends
+			IllegalArgumentException {
+
+		public IllegalBlockNameException() {
+			super();
+		}
+
+		public IllegalBlockNameException(String message, Throwable cause) {
+			super(message, cause);
+		}
+
+		public IllegalBlockNameException(String s) {
+			super(s);
+		}
+
+		public IllegalBlockNameException(Throwable cause) {
+			super(cause);
+		}
+
+		@Override
+		public String toString() {
+			return "IllegalBlockNameException []";
+		}
+
+	}
+
+	private static final BlockWithDataOrDontcare AIR = new BlockWithDontcare(0);
 	protected final int blockIdWithMeta;
 
 	public BlockWithDataOrDontcare(int blockWithMeta) {
 		blockIdWithMeta = blockWithMeta;
 	}
 
+	/**
+	 * Convers a string to a block with data. Also accepts the blocktype:meta
+	 * for specifying subtypes and prefixes.
+	 * 
+	 * @param blockWithMeta
+	 *            The string to look up
+	 * @return The BlockWithData object
+	 * @throws IllegalBlockNameException
+	 *             For illegal input.
+	 */
 	public static BlockWithDataOrDontcare getFromString(String blockWithMeta) {
 		// Works on minecraft:dirt:1
-		Matcher matcher = Pattern.compile("^(.+?)(?:\\:(.+))?$").matcher(blockWithMeta);
+		Matcher matcher = Pattern.compile("^([\\w\\:]+?)(?:\\:(\\w+))?$").matcher(
+				blockWithMeta);
 		if (!matcher.matches()) {
-			throw new IllegalArgumentException(
-					"Illegal block name: " + blockWithMeta);
+			throw new IllegalBlockNameException("Illegal block name: "
+					+ blockWithMeta);
 		}
+		// Air handled specially. Minecraft returns it on invalid names.
+		if (Pattern.compile("^(minecraft\\:)air$").matcher(blockWithMeta)
+				.matches()) {
+			return AIR;
+		}
+
 		Block block = (Block) Block.blockRegistry.getObject(matcher.group(1));
-		if (block == null) {
+		if (block == null || block == Blocks.air) {
 			// minecraft:dirt case
 			block = (Block) Block.blockRegistry.getObject(blockWithMeta);
 			matcher = null;
 		}
-		if (block == null) {
-			throw new IllegalArgumentException(
+		if (block == null || block == Blocks.air) {
+			throw new IllegalBlockNameException(
 					"Could not understand block name: " + blockWithMeta);
-		} else if (matcher == null || matcher.group(2) == null || matcher.group(2).matches("\\*?")) {
+		} else if (matcher == null || matcher.group(2) == null
+				|| matcher.group(2).matches("\\*?")) {
 			return new BlockWithDontcare(block);
-		} else if (matcher.group(2).matches("(1[0-5]|\\d)")) {
+		} else if (matcher.group(2).matches("^(1[0-5]|\\d)$")) {
 			int meta = Integer.parseInt(matcher.group(2));
 			return new BlockWithData(block, meta);
 		} else {
@@ -42,6 +92,36 @@ public static BlockWithDataOrDontcare getFromString(String blockWithMeta) {
 		}
 	}
 
+	public static ArrayList<String> getAllStrings() {
+		Set<ResourceLocation> keys = Block.blockRegistry.getKeys();
+		ArrayList<String> strings = new ArrayList<>();
+		for (ResourceLocation k : keys) {
+			// candidate found
+			strings.add(k.toString());
+
+			Block b = (Block) Block.blockRegistry.getObject(k);
+			HashSet<IBlockState> states = new HashSet<IBlockState>();
+			for (int i = 0; i < 16; i++) {
+				try {
+				IBlockState state = b.getStateFromMeta(i);
+				if (!states.contains(state)) {
+					states.add(state);
+				}
+				} catch (IllegalArgumentException e) {
+					// ignored
+				}
+			}
+			if (states.size() > 1) {
+				for (IBlockState state : states) {
+					BlockWithData withData = new BlockWithData(b,
+							b.getMetaFromState(state));
+					strings.add(k + ":" + withData.getMetaString());
+				}
+			}
+		}
+		return strings;
+	}
+
 	public Block getBlock() {
 		return Block.getBlockById(getBlockId());
 	}
@@ -72,4 +152,5 @@ protected String getBlockString() {
 	public abstract boolean containedIn(BlockSet blockSet);
 
 	public abstract ItemWithSubtype getItemType();
+
 }