Routines (alphabetical) > Routines: H > HDF Routines > HDF_AN_TAGREF2ID

# HDF_AN_TAGREF2ID

This function returns the HDF AN identifier of the annotation specified by its HDF tag and its HDF reference number.

## Syntax

Result = HDF_AN_TAGREF2ID(Annotation_id, Annotation_tag, Annotation_ref)

## Return Value

Returns the annotation identifier (Annotation_id) if successful or FAIL (-1) otherwise.

## Arguments

### Annotation_id

HDF_AN_ INTERFACE identifier returned by HDF_AN_START.

### Annotation_tag

HDF tag of the annotation. Valid values are:

- 104 = data label (DFTAG_DIL)
- 105 = data description (DFTAG_DIA)
- 100 = file label (DFTAG_FID)
- 101 = file description (DFTAG_FD)

### Annotation_ref

HDF reference number of the annotation.

## Keywords

None

## Version History

5.2 | Introduced