diff --git a/knowledge base/jq.md b/knowledge base/jq.md
index 4688481..d902f39 100644
--- a/knowledge base/jq.md	
+++ b/knowledge base/jq.md	
@@ -3,41 +3,66 @@
 ## TL;DR
 
 ```sh
-# add a field
+# Add a key.
 jq --arg REGION ${AWS_REGION} '.spec.template.spec.containers[]?.env? += [{name: "AWS_REGION", value: $REGION}]' /tmp/service.kube.json
 
-# delete a field
+# Delete a key.
 jq 'del(.items[].spec.clusterIP)' /tmp/service.kube.json
 
-# update a field
+# Change a value.
+jq '.extensionsGallery
+    | .serviceUrl |= "https://marketplace.visualstudio.com/_apis/public/gallery"' \
+  /usr/lib/code/product.json
 jq --arg NAMESPACE ${NAMESPACE} '.spec.template.spec.containers[]?.env[]? |= {name: .name, value: (if .name == "KUBERNETES_NAMESPACE" then $NAMESPACE else .value end)}' /tmp/service.kube.json
 
-# sort keys
+# Change multiple values at once.
+jq '.extensionsGallery
+    | .serviceUrl = "https://marketplace.visualstudio.com/_apis/public/gallery"
+    | .cacheUrl = "https://vscode.blob.core.windows.net/gallery/index"
+    | .itemUrl = "https://marketplace.visualstudio.com/items"' \
+  /usr/lib/code/product.json
+jq '.extensionsGallery + {
+       serviceUrl: "https://marketplace.visualstudio.com/_apis/public/gallery",
+       cacheUrl: "https://vscode.blob.core.windows.net/gallery/index",
+       itemUrl: "https://marketplace.visualstudio.com/items"
+    }' /usr/lib/code/product.json
+
+# Sort all the keys.
 jq --sort-keys '.' input.json > output.json
 
-# put specific keys on top
+# Put specific keys on top.
 jq '.objects = [(.objects[] as $in | {type,name,id} + $in)]' prod/dataPipeline_deviceLocationConversion_prod.json
 
-# convert enpass' json export to yaml file
+# Convert Enpass' JSON export to a YAML file
 jq '.items[] | {title, fields} | .title + ":", (.fields[] | select(.value != "") | "  " + .label + ": " + .value)' test.json -cr
 
-# datapipeline definition refactor
-for definition_file in $(find prod -type f -name "*.json")
-do
-  jq --sort-keys '.' ${definition_file} > /tmp/sorted.json
-  jq '.objects = [(.objects[] as $in | {type,name,id} + $in | with_entries(select(.value != null)))]' /tmp/sorted.json > /tmp/reordered.json
-  mv /tmp/reordered.json ${definition_file}
-done
+# Refactor a datapipeline definition.
+jq --sort-keys '.' datapipeline.json > /tmp/sorted.json \
+&& jq '.objects = [(.objects[] as $in | {type,name,id} + $in | with_entries(select(.value != null)))]' \
+     /tmp/sorted.json > /tmp/reordered.json \
+&& mv /tmp/reordered.json datapipeline.json
 
-# extract data from elements with specific keys
-kubectl get pods -o yaml | yq -y '.items[] | select(.metadata.name | test("^runner-.*")) | select(.spec.tolerations[].key == "component" and .spec.tolerations[].value == "big-runner") | .spec.nodeSelector, .spec.tolerations' -
+# Extract the value of elements with specific keys.
+kubectl get pods -o yaml \
+| yq -y '
+    .items[]
+    | select(.metadata.name | test("^runner-.*"))
+    | select(.spec.tolerations[].key == "component" and .spec.tolerations[].value == "big-runner")
+    | .spec.nodeSelector, .spec.tolerations' \
+    -
 
-# recursively find all the properties whose key is 'errors' whether it exists or not
-# '..' unrolls the object, '?' checks for the value or returns null, and 'select(.)' is like a filter on truthy values
+# Recursively find all the properties whose key is 'errors' whether it exists or not.
+# '..' unrolls the object, '?' checks for the value or returns null, and 'select(.)' is like a filter on truthy values.
 jq '[.. | .errors?[0] | select(.) ]' /tmp/helm.template.out.json
 
-# find all images in a helm chart explicitly or implicitly using the tag 'latest'
-helm template ${CHART} | yq -r '.. | .image? | select(.) | select(.|test(".*:.*")|not), select(.|test(".*:$")), select(.|test(".*:latest"))' -
+# Find all images in a helm chart explicitly or implicitly using the tag 'latest'.
+helm template chartName \
+| yq -r '
+    ..
+    | .image?
+    | select(.)
+    | select(.|test(".*:.*")|not), select(.|test(".*:$")), select(.|test(".*:latest"))' \
+    -
 ```
 
 ## Further readings
@@ -50,6 +75,8 @@ helm template ${CHART} | yq -r '.. | .image? | select(.) | select(.|test(".*:.*"
 
 - [Filter objects list with regex]
 - [Select multiple conditions]
+- [Change multiple values at once]
 
+[change multiple values at once]: https://stackoverflow.com/questions/47355901/jq-change-multiple-values#47357956
 [filter objects list with regex]: https://til.hashrocket.com/posts/uv0bjiokwk-use-jq-to-filter-objects-list-with-regex
 [select multiple conditions]: https://stackoverflow.com/questions/33057420/jq-select-multiple-conditions#33059058