Document validation and header extraction flow

```mermaid
flowchart LR
%% Define overall subgraph for clarity
subgraph ValidationRequest

A((start))
A --> B

subgraph Serial Chain
B(syntax_validation)
C(parse_info)
D("gherkin (blockers)")

B -->|Valid| C
C -->|Valid| D
end

B -->|Invalid| stop1((Stop))
C -->|Invalid| stop2((Stop))
D -->|Invalid| stop3((Stop))

subgraph Parallel Group
E(schema_validation)
%%F(bsdd_validation)
G["normative_rules"]
H["gherkin_ia"]
I["gherkin_ip"]
J(industry_practices)
end

D --> E
%%D --> F
D --> G
G --> H
G --> I
D --> J

end
```