diff --git a/Projects/Superalgos/Icons/Thumbs.db b/Projects/Superalgos/Icons/Thumbs.db
index 62461ddde..2238ee394 100644
Binary files a/Projects/Superalgos/Icons/Thumbs.db and b/Projects/Superalgos/Icons/Thumbs.db differ
diff --git a/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-016-tutorial-step-working-with-versions.json b/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-016-tutorial-step-working-with-versions.json
index f4594e308..2e0616286 100644
--- a/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-016-tutorial-step-working-with-versions.json
+++ b/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-016-tutorial-step-working-with-versions.json
@@ -6,7 +6,7 @@
         "text": "Let's say you want to test a strategy with different sets of parameters, so you take a backup of the Trading Parameters node!",
         "updated": 1615571330616,
         "icon": {
-            "name": "backup-entity",
+            "name": "hand-drag",
             "project": "Superalgos"
         }
     },
diff --git a/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-019-tutorial-step-irrelevant-nodes.json b/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-019-tutorial-step-irrelevant-nodes.json
index e28822205..69100b02e 100644
--- a/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-019-tutorial-step-irrelevant-nodes.json
+++ b/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-019-tutorial-step-irrelevant-nodes.json
@@ -13,8 +13,8 @@
     "paragraphs": [
         {
             "style": "Text",
-            "text": "This means that you may keep as many structures of nodes detached from hierarchies as long as you wish, keeping them at hand for later use, or for whatever reason.",
-            "updated": 1615575641085
+            "text": "This means that you may keep as many structures of nodes detached from hierarchies, for as long as you wish, keeping them at hand for later use, or for whatever reason.",
+            "updated": 1615580307483
         },
         {
             "style": "Success",
diff --git a/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-021-tutorial-step-nodes-attaching-rules.json b/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-021-tutorial-step-nodes-attaching-rules.json
new file mode 100644
index 000000000..92d2620a5
--- /dev/null
+++ b/Projects/Superalgos/Schemas/Docs-Tutorials/basic-education-021-tutorial-step-nodes-attaching-rules.json
@@ -0,0 +1,30 @@
+{
+    "tutorial": "Basic Education",
+    "pageNumber": "21",
+    "type": "Tutorial Step - Nodes' Attaching Rules",
+    "definition": {
+        "text": "Click the help button on the Trading Parameters node to access the node's Docs page. I'm going to show you something...",
+        "icon": {
+            "name": "help",
+            "project": "Superalgos"
+        },
+        "updated": 1615580946356
+    },
+    "paragraphs": [
+        {
+            "style": "Callout",
+            "text": "Scroll the page all the way to the bottom until you find the Trading Parameters Attaching Rules title.",
+            "updated": 1615583276420
+        },
+        {
+            "style": "Text",
+            "text": "Each node may be attached to certain node types. These attaching rules are listed on the node's page in the Docs.",
+            "updated": 1615583315164
+        },
+        {
+            "style": "Success",
+            "text": "When there are several nodes that may accept the connection, each candidate displays a grey ring indicating their readiness to take the attachment. Only the candidate closer to the node to be attached is highlighted in orange.",
+            "updated": 1615582903959
+        }
+    ]
+}
\ No newline at end of file