diff --git a/docs/branch/py4lexis4-cmd.md b/docs/branch/py4lexis4-cmd.md
index fee98a5..388db53 100644
--- a/docs/branch/py4lexis4-cmd.md
+++ b/docs/branch/py4lexis4-cmd.md
@@ -99,6 +99,207 @@ def less(self, local_specifier: str, remote_specifier: str, ...):
 
 ---
 
+### Parameter Parsing Deep Dive
+
+#### Current Flow: CLI → Command
+
+```
+CLI Input: owi remote ls all files="['**/*']" format=wide
+
+                    ↓ Click captures
+
+@click.argument('subcmd')                  # "ls"
+@click.argument('specifier')               # "all"  
+@click.argument('args', nargs=-1)          # ("files=['**/*']", "format=wide")
+
+                    ↓ extract_args()
+
+args = []
+kwargs = {"files": "['**/*']", "format": "wide"}
+
+                    ↓ RemoteCommands.do()
+
+                    ↓ _cast_args(func, args, kwargs)
+
+Pydantic TypeAdapter converts types based on function signature
+```
+
+#### `extract_args()` in cli.py (Lines 212-238)
+
+```python
+def extract_args(args):
+    """
+    Separates positional and keyword arguments from CLI args.
+    - Keyword: contains '=' and NOT wrapped in '{...}'
+    - Positional: everything else
+    - Escape: wrap in {} to pass literal '=' (e.g., "{a=b}")
+    """
+    def is_kwargs(x: str):
+        return "=" in x and not (x.startswith('{') and x.endswith('}'))
+    
+    kwargs = {k[0]: k[1] for k in [f.split("=", 1) for f in args if is_kwargs(f)]}
+    args = [arg for arg in args if not is_kwargs(arg)]
+    return args, kwargs
+```
+
+**Issues:**
+1. Non-standard: `key=value` instead of `--key value`
+2. String escaping awkward: `files="['**/*']"` (needs quotes)
+3. `{...}` escape mechanism undocumented
+4. `-` to `_` conversion (e.g., `pq-batch-size` → `pq_batch_size`)
+
+#### `_cast_args()` in base.py (Lines 240-307)
+
+```python
+def _cast_args(self, func, args, kwargs):
+    """
+    Uses pydantic TypeAdapter to convert args/kwargs to match 
+    function signature types.
+    """
+    sig = inspect.signature(func)
+    for param in sig.parameters.values():
+        if param.annotation != inspect.Parameter.empty:
+            type_adapter = TypeAdapter(expected_type)
+            converted = type_adapter.validate_python(value)
+```
+
+**Pros:**
+- Automatic type conversion (str → int, str → bool)
+- Validation via pydantic
+
+**Cons:**
+- Complex error handling
+- Hidden behavior (user doesn't see types)
+
+#### Example: Query Less Command
+
+```bash
+# Current syntax
+owi query less --local . --remote main:latest select=url,title limit=10
+
+# Parsed as:
+subcmd = "less"
+local = "."
+remote = "main:latest"
+args = []
+kwargs = {"select": "url,title", "limit": "10"}  # ← limit is string!
+
+# _cast_args converts:
+kwargs = {"select": "url,title", "limit": 10}  # ← now int
+```
+
+---
+
+### Specifier Format (KEEP)
+
+The specifier is a powerful mini-DSL for dataset selection. **✅ Worth keeping and documenting properly.**
+
+#### Syntax
+
+```
+<datacenter>:<day>#<duration>/<filter1>=<value1>;<filter2>=<value2>/...
+```
+
+#### Components
+
+| Part | Format | Required | Default | Example |
+|------|--------|----------|---------|---------|
+| `datacenter` | `all`, `lrz`, `it4i`, `csc` | Yes | `all` | `lrz` |
+| `day` | `YYYY-MM-DD`, `latest`, `*` | No | - | `2024-03-24`, `latest` |
+| `duration` | `#N` (days) | No | - | `#7` (last 7 days) |
+| `filters` | `/key=value;key=value` | No | - | `/access=public` |
+
+#### Parsing (manager.py:772-819)
+
+```python
+def parse_specifier(self, specifier: str) -> dict:
+    """
+    Regex: ^(?P<data_center>[\w-]+)(?::(?P<day>[\d-]+|latest)(?:#(?P<duration>\d+))?)?$
+    """
+    result = {
+        'data_center': None,   # "lrz", "it4i", "csc", None for "all"
+        'day': None,           # datetime or "latest"
+        'duration': None,      # int (days)
+        'query': {}            # {"key": "value", ...}
+    }
+```
+
+#### Examples
+
+| Specifier | Meaning |
+|-----------|---------|
+| `all` | All datasets from all data centers |
+| `lrz:latest` | Latest datasets from LRZ |
+| `it4i:2024-03-24` | Datasets from IT4I on specific date |
+| `csc:2024-01#7` | CSC datasets, Jan 2024, 7 days |
+| `all/access=public` | All public datasets |
+| `lrz:latest/collectionName=curlie` | Latest Curlie from LRZ |
+| `all/id=f6ea5756-...` | Specific dataset by ID |
+
+#### Design Recommendations for Typer
+
+Keep specifier as a **first positional argument** for brevity:
+
+```bash
+# Current (good - keep)
+owi remote ls lrz:latest
+owi remote pull all:2024-01#7/access=public
+
+# Alternative with Typer (proposed)
+owi remote ls lrz:latest          # Argument
+owi remote ls --spec lrz:latest   # Option (if needed for clarity)
+```
+
+---
+
+### Typer Migration: Parameter Strategy
+
+#### Proposed Conventions
+
+| Element | Typer | Example |
+|---------|-------|---------|
+| Required positional | `typer.Argument()` | `specifier: str` |
+| Optional with default | `typer.Option()` | `--limit 10` |
+| Boolean flags | `typer.Option(is_flag=True)` | `--verbose` |
+| Multiple values | `List[str]` | `--file f1 --file f2` |
+
+#### Example: `owi remote ls`
+
+**Current:**
+```bash
+owi remote ls all format=wide files="['**/*']" no_summary=true
+```
+
+**Proposed Typer:**
+```bash
+owi remote ls all --format wide --files "**/*" --no-summary
+owi remote ls lrz:latest -f wide --files "**/*"
+```
+
+**Implementation:**
+```python
+@remote_app.command()
+def ls(
+    specifier: str = typer.Argument("all", help="Dataset specifier"),
+    format: str = typer.Option("short", "--format", "-f", help="Output format"),
+    files: Optional[str] = typer.Option(None, help="File glob pattern"),
+    no_summary: bool = typer.Option(False, "--no-summary", help="Skip summary"),
+    details: bool = typer.Option(False, "--details", "-l", help="Show details")
+):
+    """List datasets matching SPECIFIER."""
+```
+
+#### Balancing Brevity and Extensibility
+
+| Goal | Approach |
+|------|----------|
+| Short commands | Specifier as positional `Argument` |
+| Common options | Short aliases (`-f`, `-l`, `-v`) |
+| Extensibility | All other options as `--key value` |
+| Backward compat | Support `key=value` via custom parser (optional) |
+
+---
+
 ### Documentation
 
 | Location | Content |