What's the default value of p_cccd_md

[sprhawk]

ble_gatts_attr_md_t* p_cccd_md; /**< Attribute metadata for the Client Characteristic Configuration Descriptor, or NULL for default values. */

What's the default value ?

and for p_sccd_md.

[John]

You should read the answer to this question:

CCCD answer

Also read the section of the specification referenced in the answer as it addresses the default value.