3.29. Pres_Ref - Presence of Referent

3.29.1. Description

Records whether an object or action is physically present when it is referenced in gesture

3.29.2. Format

entry    ::=  code_set [op code_set]*
code_set ::=  (null | code) [set_op (null | code)]*
null     ::=  "X"
code     ::=  "Y" | "N" | "UC"
set_op   ::=  "/"
op       ::=  ";"

3.29.3. Values

Codes have the following interpretations:

Code	Meaning	Description
Y	Yes	Gesturer can see the object or action (or its location) that is referred to in gesture
N	No	Gesturer cannot see the object or action (or its location) that is referred to in gesture
UC	Unclear	Gesture refers to an object or action that is not visible to the camera but which might be present (e.g. something on a computer screen or in a book)
X	Null	Gesture refers to something that cannot have a physical referent

Ops have the following interpretations:

Op	Meaning
;	Separates all codes
/	Used to combine representational codes into single units

3.29.4. Vertical Dependencies

None

3.29.5. Horizontal Dependencies

Pres_Ref is dependent on the G_Type Column.

X is only allowed when the corresponding G_Type code is C, E, FA, or G, and is required when G_Type is E. Otherwise, a non-X code is required.

3.29.6. Depended Upon By

None