diff --git a/dtmrepo b/dtmrepo
index 2ab2274..6d29ca1 100755
--- a/dtmrepo
+++ b/dtmrepo
@@ -16,6 +16,7 @@ ISREGISTERED="Current"
 
 LOCALMARKER="local:"
 SPACEWALKMARKER="swalk:"
+MIRRORMARKER="mirror:"
 
 usage() {
     echo
@@ -308,6 +309,11 @@ update_repo() {
         _REPOID=${_REPOSPEC[1]}
         spacewalk_enable ${_DISTRO} || return 1
         _SWALK=1
+    elif [ "${_REPOID:0:${#MIRRORMARKER}}" == "${MIRRORMARKER}" ]; then
+        IFS=: read -ra _REPOSPEC <<<${_REPOID}
+        _REPOID=${_REPOSPEC[1]}
+        _SYNCALL=''
+        _DELETE='-d'
     fi
 
     (
@@ -358,6 +364,9 @@ download_package() {
         _REPOID=${_REPOSPEC[1]}
         spacewalk_enable ${_DISTRO} || return 1
         _SWALK=1
+    elif [ "${_REPOID:0:${#MIRRORMARKER}}" == "${MIRRORMARKER}" ]; then
+        IFS=: read -ra _REPOSPEC <<<${_REPOID}
+        _REPOID=${_REPOSPEC[1]}
     fi
 
     (
@@ -408,7 +417,7 @@ gen_repodata() {
 
     if [ "${SELECT}" -eq 1 ]; then
         _PROTECTREPO=1
-    elif [ "${MIRROR}" -eq 1 ]; then
+    elif [ "${MIRROR}" -eq 1 -o "${_REPOID:0:${#MIRRORMARKER}}" == "${MIRRORMARKER}" ]; then
         _PROTECTREPO=1
     elif [ ! -z "${protectrepo}" ]; then
         echo ${_REPODIR} | egrep -q "$(echo ${protectrepo} | sed -r 's/[ ,]+/|/g')" && _PROTECTREPO=1
diff --git a/instructions.txt b/instructions.txt
index 09ac111..1c8af0c 100644
--- a/instructions.txt
+++ b/instructions.txt
@@ -87,6 +87,7 @@ This will register and initialise dtmrepo. During registration it will ask for y
     epel = epel-5-x86_64
     foo = local:/var/dtmrepo/foo/el5/x86_64
     misc = swalk:some-spacewalk-channel
+    dev = mirror:dev-el5
     ====================================================
 
     There are two sections: [control] and [repos]. The [control] section may override some of the global configuration options. In the example above it overrides the the number of package versions to keep. The [repos] section defines the different repositories that will be synced. The format is "targetdir = repoid". The targetdir corresponds to the directory REPDODIR/rhel5s-x86_64/targetdir and repoid is a real yum repository that is preconfigured under INSTALLDIR/etc/dtmrepo.repos.d/.
@@ -106,6 +107,8 @@ This will register and initialise dtmrepo. During registration it will ask for y
 
     Put the repo configurations under the directory specified in "reposdir" of the custom yum configuration specified in "yumconf" of INSTALLDIR/etc/dtmrepo.conf.
 
+    If the repoid is prefixed by "mirror:" then an update operation will mirror that repo. Local packages that are no longer present in the source repo will be deleted.
+
     The second type of repoid is not a real repository but just a collection of packages stored in a directory somewhere. This is specified by the identifier local:. In the example above, /var/dtmrepo/foo/el5/x86_64 need not contain a repodata. If the directory already exists where it's supposed to be under repodata (i.e. /var/dtmrepo/rhel5s-x86_64/foo) then it is left untouched otherwise a symlink that points to the source directory is created under the said repodata.
 
     The third type of repoid is for Spacewalk channels. For this to work, the dtmrepo server needs to be registered with Spacewalk obviously. If the distro matches the distro of the dtmrepo server then the "swalk" marker is not needed. If the distro is a "fake" distro, i.e. you are fetching EL7 packages from a EL6 dtmrepo server, then you need to register first (see Section IV) and the "swalk" marker is required.
@@ -159,7 +162,8 @@ dtmrepo accepts several commandline options namely:
     -r : comma-separated list of repos to process. If not specified then all repos are processed
     -u : sync packages
     -g : generate repodata
-    -s : download selected packages and all dependencies. This option disables -u and temporarily protects the entire repo so that the packages are not deleted during repodata creation. Has no effect on "local:" repos.
+    -m : mirror; implies -a, -u and -g
+    -s : download selected packages and all dependencies. This option disables -u and temporarily protects the entire repo so that the packages are not deleted during repodata creation. Has no effect on "local:" repos. Automatically performs -g.
     -p : purge undeclared repo directories
     -f : force the operation. Normally, dtmrepo will not attempt to generate new repodata if it's newer than any package in the repo.
     -x : autofix. Red Hat subscription-manager automatically updates the subscription certificate. This option automatically updates master.repo with the new cert.
@@ -183,6 +187,9 @@ VI. Usage Examples
     dtmrepo -ug -r epel
         sync and generate repo data for epel on all distros
 
+    dtmrepo -mv -r epel
+        mirror the epel repo for all distros
+
     dtmrepo -u -r foo,bar
         sync foo and bar repos on all distros