diff --git a/docs/index.md b/docs/index.md
index d0d4f7e769e9db7ed67f96b08eff575785c5dd6f..071f82181c36704c39bb9581ea58707b9e1d88bf 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -41,18 +41,18 @@ The tool supports verification and mapping across diagnostic coding formats belo
 
 ## Phenotype Definition
 
-### **Phenotype directory structure
+### **Phenotype directory structure**
 
 ```
 workspace/                          # Default workspace directory
 ├── phen/                           # Default phenotype directory
 │   ├── codes/                      # Phenotype source concept code lists directory
 │   ├── concept-set/                # Processed phenotype concept sets in CSV format
-│   ├── map/                         # Process mapping from source to target code types
-│   │   ├── errors/                 # Errors recorded during mapping
-│   ├── omop/                        # Processed phenotype concept sets in OMOP database CSV files
-│   ├── config.yaml                  # Phenotype configuration file
-│   ├── vocab_versions.yaml          # Versions file for vocabularies used to generate concept sets
+│   ├── map/                        # Process mapping from source to target code types
+│   │   ├── errors/                 # Errors recorded during mapping process
+│   ├── omop/                       # Processed phenotype concept sets in OMOP database CSV files
+│   ├── config.yaml                 # Phenotype configuration file
+│   ├── vocab_versions.yaml         # Versions file for vocabularies used to generate concept sets
 ``` 
 
 ### **Configuration File**