xz: Document that threaded decompression hasn't been implemented yet.
diff --git a/src/xz/xz.1 b/src/xz/xz.1
index 75aead3..bc5514d 100644
--- a/src/xz/xz.1
+++ b/src/xz/xz.1
@@ -5,7 +5,7 @@
.\" This file has been put into the public domain.
.\" You can do whatever you want with this file.
.\"
-.TH XZ 1 "2014-12-16" "Tukaani" "XZ Utils"
+.TH XZ 1 "2015-05-11" "Tukaani" "XZ Utils"
.
.SH NAME
xz, unxz, xzcat, lzma, unlzma, lzcat \- Compress or decompress .xz and .lzma files
@@ -1055,6 +1055,14 @@
can be overriden with the
.BI \-\-block\-size= size
option.
+.IP ""
+Threaded decompression hasn't been implemented yet.
+It will only work on files that contain multiple blocks
+with size information in block headers.
+All files compressed in multi-threaded mode meet this condition,
+but files compressed in single-threaded mode don't even if
+.BI \-\-block\-size= size
+is used.
.
.SS "Custom compressor filter chains"
A custom filter chain allows specifying
