diff --git a/tools/tools/git/git-arc.sh b/tools/tools/git/git-arc.sh
--- a/tools/tools/git/git-arc.sh
+++ b/tools/tools/git/git-arc.sh
@@ -147,6 +147,8 @@
     exit 1
 }
 
+# Looks up Phabricator Internal ID (PHID) for a given Revision ID.
+# The input must match regex D[1-9][0-9]* (i.e D1234)
 diff2phid()
 {
     local diff
@@ -161,6 +163,13 @@
         jq -r "select(.response != []) | .response.${diff}.phid"
 }
 
+# Prints status of a given Differential Revision
+# The output looks like:
+# closed         my awseome feature
+#
+# TODO: improvement to avoid calling jq twice
+# jq_output=$(jq -r "select(.response != []) | .response.${diff} | (.status, .fullName) | @text \"%-14s %s\"" < "$json")
+printf "$jq_output\n"
 diff2status()
 {
     local diff tmp status summary
@@ -179,6 +188,13 @@
     printf "%-14s %s\n" "${status}" "${summary}"
 }
 
+
+# log2diff: Extract the Differential Revision identifier from the commit
+#         message of a given commit.
+# Usage:  log2diff <commit>
+# Input:  A Git commit hash or reference.
+# Output: Echoes the extracted Differential Revision id (e.g., D1234)
+#         if found and unique, or an empty string otherwise.
 log2diff()
 {
     local diff
@@ -194,6 +210,14 @@
 
 # Look for an open revision with a title equal to the input string.  Return
 # a possibly empty list of Differential revision IDs.
+#
+# title2diff:   Search for the Differential Revision identifier (e.g., D1234)
+#               by matching the input title against the titles fetched from the
+#               'arc list' command.
+# Usage:        title2diff <title>
+# Input:        A string representing the title of a Differential Revision.
+# Output:       Echoes the corresponding Differential Revision identifier
+#               (e.g. D1234) if a matching title is found, or nothing otherwise.
 title2diff()
 {
     local title
@@ -464,18 +488,18 @@
     # freebsd.org (which isn't surprising for ports committers getting src
     # commits reviewed).
     case "${addr}" in
-    *.*) ;;		# external user
+    *.*) ;;             # external user
     *)
-	echo "${name} <${addr}@FreeBSD.org>"
-	return
-	;;
+        echo "${name} <${addr}@FreeBSD.org>"
+        return
+        ;;
     esac
 
     # Choice 2: authorAddr and authorName were set somehow in the bundle, so use
     # that. We may need to filter some known bogus ones, should they crop up.
     if [ -n "$authorName" -a -n "$authorAddr" ]; then
-	echo "${authorName} <${authorAddr}>"
-	return
+        echo "${authorName} <${authorAddr}>"
+        return
     fi
 
     # Choice 3: We can find this user in the FreeBSD repo. They've submited
@@ -483,8 +507,8 @@
     # similar to their phab username.
     email=$(git log -1 --author "$(echo ${addr} | tr _ .)" --pretty="%aN <%aE>")
     if [ -n "${email}" ]; then
-	echo "${email}"
-	return
+        echo "${email}"
+        return
     fi
 
     # Choice 4: We know this user. They've committed before, and they happened
@@ -492,11 +516,11 @@
     # might not be a good idea, since names can be somewhat common (there
     # are two Andrew Turners that have contributed to FreeBSD, for example).
     if ! (echo "${name}" | grep -w "[Uu]ser" -q); then
-	email=$(git log -1 --author "${name}" --pretty="%aN <%aE>")
-	if [ -n "$email" ]; then
-	    echo "$email"
-	    return
-	fi
+        email=$(git log -1 --author "${name}" --pretty="%aN <%aE>")
+        if [ -n "$email" ]; then
+            echo "$email"
+            return
+        fi
     fi
 
     # Choice 5: Wing it as best we can. In this scenario, we replace the last _
@@ -523,13 +547,13 @@
     # Get the author phid for this patch
     review_data=$(echo '{
                   "constraints": {"phids": ["'"$reviewid"'"]}
-		}' |
+                }' |
         arc_call_conduit -- differential.revision.search)
     authorid=$(echo "$review_data" | jq -r '.response.data[].fields.authorPHID' )
     # Get metadata about the user that submitted this patch
     user_data=$(echo '{
                   "constraints": {"phids": ["'"$authorid"'"]}
-		}' |
+                }' |
             arc call-conduit -- user.search | grep -v ^Warning: |
             jq -r '.response.data[].fields')
     user_addr=$(echo "$user_data" | jq -r '.username')
@@ -541,17 +565,17 @@
     # remove duplicates 'just to be sure' since we've not seen multiple
     # records that match.
     diff_data=$(echo '{
-		"revisionIDs": [ '"${diff#D}"' ]
-		}' | arc_call_conduit -- differential.querydiffs |
-	     jq -r '.response | flatten | .[]')
+                "revisionIDs": [ '"${diff#D}"' ]
+                }' | arc_call_conduit -- differential.querydiffs |
+             jq -r '.response | flatten | .[]')
     author_addr=$(echo "$diff_data" | jq -r ".authorEmail" | grep -v null | sort -u)
     author_name=$(echo "$diff_data" | jq -r ".authorName" | grep -v null | sort -u)
     author=$(find_author "$user_addr" "$user_name" "$author_addr" "$author_name")
 
     # If we had to guess, and the user didn't want to guess, abort
     if [ "${author}" = "ABORT" ]; then
-	warn "Not committing due to uncertainty over author name"
-	exit 1
+        warn "Not committing due to uncertainty over author name"
+        exit 1
     fi
 
     tmp=$(mktemp)
@@ -581,7 +605,7 @@
     while getopts c o; do
         case "$o" in
         c)
-	    require_clean_work_tree "patch -c"
+            require_clean_work_tree "patch -c"
             commit=true
             ;;
         *)
@@ -595,9 +619,9 @@
         arc patch --skip-dependencies --nocommit --nobranch --force "$rev"
         echo "Applying ${rev}..."
         [ $? -eq 0 ] || break
-	if $commit; then
-	    patch_commit $rev
-	fi
+        if $commit; then
+            patch_commit $rev
+        fi
     done
 }