Updated the YAML properties for version and pin The version property replaces the ref property because it can support a reference and a semantic version constraint. The ref property will still be supported but is deprecated. The pin property is for upcoming work on pinning.

diff --git a/README.md b/README.md
index 6aa8721..5d97527 100644
--- a/README.md
+++ b/README.md

@@ -257,7 +257,7 @@
   - package: github.com/kylelemons/go-gypsy
   - package: github.com/Masterminds/cookoo
     vcs: git
-    ref: master
+    version: master
     repo: git@github.com:Masterminds/cookoo.git
 ```
 
@@ -275,7 +275,7 @@
 `github.com/Masterminds/cookoo` in the `vendor` directory. (Note that `package`
 and `repo` can be completely different)
 
-**TIP:** The ref is either VCS dependent and can be anything that can be checked
+**TIP:** The version is either VCS dependent and can be anything that can be checked
 out or a semantic version constraint that can be parsed by the [`github.com/
 Masterminds/semver`](https://github.com/Masterminds/semver) package.
 For example, with Git this can be a branch, tag, or hash. This varies and

diff --git a/cmd/yaml.go b/cmd/yaml.go
index b1a6e2c..ce95911 100644
--- a/cmd/yaml.go
+++ b/cmd/yaml.go

@@ -428,12 +428,12 @@
 
 // Dependency describes a package that the present package depends upon.
 type Dependency struct {
-	Name, Reference, Repository string
-	VcsType                     string
-	Subpackages, Arch, Os       []string
-	UpdateAsVendored            bool
-	Flatten                     bool
-	Flattened                   bool
+	Name, Reference, Pin, Repository string
+	VcsType                          string
+	Subpackages, Arch, Os            []string
+	UpdateAsVendored                 bool
+	Flatten                          bool
+	Flattened                        bool
 }
 
 // DependencyFromYaml creates a dependency from a yaml.Node.
@@ -444,7 +444,8 @@
 	}
 	dep := &Dependency{
 		Name:        valOrEmpty("package", pkg),
-		Reference:   valOrEmpty("ref", pkg),
+		Reference:   valOrEmpty("version", pkg),
+		Pin:         valOrEmpty("pin", pkg),
 		VcsType:     getVcsType(pkg),
 		Repository:  valOrEmpty("repo", pkg),
 		Subpackages: valOrList("subpackages", pkg),
@@ -453,6 +454,12 @@
 		Flatten:     boolOrDefault("flatten", pkg, false),
 	}
 
+	// Continue to support the legacy ref property for the version. To remove
+	// support remove the following block.
+	if dep.Reference == "" {
+		dep.Reference = valOrEmpty("ref", pkg)
+	}
+
 	if dep.Name != "" {
 		orig := dep.Name
 		dep.Name = getRepoRootFromPackage(orig)
@@ -529,7 +536,10 @@
 		dep["vcs"] = yaml.Scalar(vcs)
 	}
 	if len(d.Reference) > 0 {
-		dep["ref"] = yaml.Scalar(d.Reference)
+		dep["version"] = yaml.Scalar(d.Reference)
+	}
+	if len(d.Pin) > 0 {
+		dep["pin"] = yaml.Scalar(d.Pin)
 	}
 	if len(d.Repository) > 0 {
 		dep["repo"] = yaml.Scalar(d.Repository)

diff --git a/docs/example-glide.yaml b/docs/example-glide.yaml
index f972ca2..7b27acc 100644
--- a/docs/example-glide.yaml
+++ b/docs/example-glide.yaml

@@ -20,20 +20,21 @@
   - package: github.com/kylelemons/go-gypsy
 
   # Full definition
-  # This will check out the given Git repo, set the reference to master,
+  # This will check out the given Git repo, set the version to master,
   # use "git" (not "go get") to manage it, and alias the package to the
   # import path github.com/Masterminds/cookoo
   - package: github.com/Masterminds/cookoo
     vcs: git
-    ref: master
+    version: master
     repo: git@github.com:Masterminds/cookoo.git
 
-  # Here's an example with a commit hash for a ref. Since repo is not specified,
-  # this will use git to to try to clone 'http://github.com/aokoli/goutils'
-  # and then set the revision to the given hash.
+  # Here's an example with a commit hash for a version. Since repo is not
+  # specified, this will use git to to try to clone
+  # 'http://github.com/aokoli/goutils' and then set the revision to the given
+  # hash.
   - package: github.com/aokoli/goutils
     vcs: git
-    ref: 9c37978a95bd5c709a15883b6242714ea6709e64
+    version: 9c37978a95bd5c709a15883b6242714ea6709e64
 
   # MASKING: This takes my fork of goamz (technosophos/goamz) and clones it
   # as if it were the crowdmob/goamz package. This is incredibly useful for
@@ -64,16 +65,16 @@
   - package: bzr.example.com/foo/bar/trunk
     vcs: bzr
     repo: bzr://bzr.example.com/foo/bar/trunk
-    # Only tags can be used as refs. If you'd like to change that... please
-    # submit a patch. We don't know much about bzr
-    ref: 1.0.0
+    # The version can be a branch, tag, commit id, or a semantic version
+    # constraint parsable by https://github.com/Masterminds/semver
+    version: 1.0.0
 
   - package: hg.example.com/foo/bar
     vcs: hg
     repo: http://hg.example.com/foo/bar
-    ref: ae081cd1d6cc
+    version: ae081cd1d6cc
 
-  # For SVN, the only valid ref is a commit number. Tags and branches go in
+  # For SVN, the only valid version is a commit number. Tags and branches go in
   # the repo URL.
   - package: svn.example.com/foo/bar/trunk
     vcs: svn

diff --git a/glide.yaml b/glide.yaml
index d9a3721..d35a193 100644
--- a/glide.yaml
+++ b/glide.yaml

@@ -5,12 +5,12 @@
       - yaml
     flatten: true
   - package: github.com/Masterminds/cookoo
-    ref:     master
+    version:     master
     repo:    git@github.com:Masterminds/cookoo.git
     vcs:     git
     subpackages:
       - .
   - package: github.com/Masterminds/vcs
-    ref:     ^1.0.0
+    version:     ^1.0.0
   - package: github.com/codegangsta/cli
   - package: github.com/Masterminds/semver