# Marks

# Marks

A mark flags a moment in a test, tagged by a test program as it ran or by a
person, live or later. Marks show on the [Replay](https://phloem.ai/docs/review/replay/) scrubber and charts;
**[** / **]** jump between them.

## Reading a mark

Shape says who made it; fill says whether it finished.

| Glyph | Meaning |
|---|---|
| ▲ triangle | fired by a rule in a test program |
| ● circle | placed by a person |
| filled | completed |
| hollow | never finished |

A mark is an **instant** (one glyph) or a **span** (a glyph plus an underline
with end caps). A span that never closed, such as an aborted run, shows as a
dashed band with no end cap, running to the edge of the window. A mark that
ended in an abort is drawn in the alarm colour.

Crowded marks collapse into a count chip (`12`). Click it to zoom to that group.

On the charts, a mark shows only on the channels it is **about**. A mark about
the whole run shows on every chart.

## Filtering

The **tags** button in the transport bar counts the marks in the window and
opens the tags drawer:

| Control | Does |
|---|---|
| **show on lanes** | shows or hides marks on the charts. The scrubber always shows them |
| one row per name, with its count (`pulse 14`) | its eye hides every mark with that name, on the scrubber, the charts and **[**/**]** |
| **show all** | brings back every hidden name |

To find a mark by name over a longer window, open the **tags** tab in the left
panel and type in **Filter tags**. Click a row to move the playhead there.

## Marking a moment yourself

1. Shift-drag the scrubber to select a range, or put the playhead on the moment.
2. Press **tag** beside the clock (Shift-drag opens the form for you).
3. Type a name in **tag name** (`sample-taken`, `anomaly`) and press **Save**.
   The form shows what it will mark: the dragged range, or `at` the cursor
   instant.

The mark appears once it reaches the cloud, usually after a short delay. Until
then the row says *tag saved — appears when it lands*.

> **Note:** Names starting `sys.` are reserved. Saving one is refused, with the reason.

## The anchor — t = 0

Count time from the moment that matters instead of clock time. **Alt-click**
any mark to make it time zero. A dashed `0` line appears on the scrubber and
every chart. The clock adds a second line with the offset from that moment
(`-3.2s`, `+41.0s`). The status row shows the anchor (`t=0 start`); its **×**
clears it. The anchor lasts for the session.

- [Mark an event and find it later](https://phloem.ai/docs/guides/mark-and-find/): The same, step by step
- [Replay](https://phloem.ai/docs/review/replay/): Scrub, zoom and compare runs