GITBOOK-562: Added subgraph lowercase warning message

SUMMARY.md

@@ -3,7 +3,7 @@
 * [👋 Welcome](README.md)
 * [🌊 Discover](discover/README.md)
   * [Explore](discover/explore.md)
-  * [Basic Concepts](discover/engage.md)
+  * [Basic Concepts](discover/basic-concepts.md)
   * [Ocean 101](discover/ocean-101.md)
   * [Wallets](discover/wallets/README.md)
     * [Set Up MetaMask Wallet](discover/wallets/metamask-setup.md)

developers/subgraph/README.md

@@ -10,7 +10,7 @@ description: >-
 
 The [Ocean Subgraph](https://github.com/oceanprotocol/ocean-subgraph) is built on top of [The Graph](https://thegraph.com/)(the popular :sunglasses: indexing and querying protocol for blockchain data). It is an essential component of the Ocean Protocol ecosystem. It provides an off-chain service that utilizes GraphQL to offer efficient access to information related to datatokens, users, and balances. By leveraging the subgraph, data retrieval becomes faster compared to an on-chain query. The data sourced from the Ocean subgraph can be accessed through [GraphQL](https://graphql.org/learn/) queries.
 
-Imagine this 💭: if you were to always fetch data from the on-chain, you'd start to feel a little...old :older\_woman:. Like your queries are stuck in a time warp. But fear not! When you embrace the power of the subgraph, data becomes your elixir of youth. It's snappy, it's swift, and it's refreshingly retrievable. With the subgraph, you can sail through data like a sprightly dolphin 🐬
+Imagine this 💭: if you were to always fetch data from the on-chain, you'd start to feel a little...old :older\_woman: Like your queries are stuck in a time warp. But fear not! When you embrace the power of the subgraph, data becomes your elixir of youth. It's snappy, it's swift, and it's refreshingly retrievable. With the subgraph, you can sail through data like a sprightly dolphin 🐬
 
 <div data-full-width="false">
 
@@ -36,8 +36,11 @@ If you're eager to use the Ocean Subgraph, here's some important information for
 | Mumbai              | [Subgraph](https://v4.subgraph.mumbai.oceanprotocol.com)    | [GraphiQL](https://v4.subgraph.mumbai.oceanprotocol.com/subgraphs/name/oceanprotocol/ocean-subgraph/graphql)    |
 | Görli               | [Subgraph](https://v4.subgraph.goerli.oceanprotocol.com)    | [GraphiQL](https://v4.subgraph.goerli.oceanprotocol.com/subgraphs/name/oceanprotocol/ocean-subgraph/graphql)    |
 
-Now that you're familiar with what the Ocean Subgraph is all about, get ready for some hands-on fun! In the following pages, we've prepared a few examples just for you. From running queries to exploring fascinating data, you'll have the chance to dive right into the Ocean Subgraph data. There, you'll find a wide range of additional code snippets and projects that showcase the power and versatility of the Ocean Subgraph. So, grab a virtual snorkel, and let's explore together! 🤿\
-\
+{% hint style="warning" %}
+When making subgraph queries, please remember that the parameters you send, such as a datatoken address or a data NFT address, should be in **lowercase**. This is an essential requirement to ensure accurate processing of the queries. We kindly request your attention to this detail to facilitate a seamless query experience.
+{% endhint %}
+
+In the following pages, we've prepared a few examples just for you. From running queries to exploring data, you'll have the chance to dive right into the Ocean Subgraph data. There, you'll find a wide range of additional code snippets and examples that showcase the power and versatility of the Ocean Subgraph. So, grab a virtual snorkel, and let's explore together! 🤿\
 
 
 {% hint style="info" %}