Yes, it is normal.
Messages, such as MT799 and MT999, contain free text as defined by the MT 2017 standard. These messages are not structured and may include in a narrative format the reference to the document dossier they should refer to. Please take into consideration, that there is likelihood messages not to contain a reference number at all.
It is therefore essential that these messages be reviewed by an operator before being attached to an existing dossier.
PTM provides a mechanism for this through the Unrecognized Documents screen.
