--- a/Sphinx/source/faq.rst	Sat Feb 02 12:15:28 2019 +0100
+++ b/Sphinx/source/faq.rst	Sat Feb 02 17:39:00 2019 +0100
@@ -16,6 +16,7 @@
    faq/scalability.rst
    faq/features.rst
    faq/rest-samples.rst
+   faq/series-completion.rst
    faq/proprietary.rst
 
 Features supported by Orthanc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Sphinx/source/faq/series-completion.rst	Sat Feb 02 17:39:00 2019 +0100
@@ -0,0 +1,11 @@
+What do the various status displayed in a series header mean?
+=============================================================
+
+A series can be assigned a status by Orthanc. I can list as *unknown*, *missing*, *inconsistent* or *complete*.
+
+The status is meant to convey the completeness of the series, as known by Orthanc.
+
+As a general rule, since there is no generic DICOM tag that contains the number of DICOM instances that are contained in a given series, and since there is no generic tag that contains the index of a DICOM instance inside its parent series, it is in general impossible to know if a series is complete in terms of its instances. This is the meaning of the *Unknown* status displayed by Orthanc.
+
+However, for some types of images (such as cardiac MRI), the DICOM modules might specify a tag that contains this information. If such a tag is available for a series, Orthanc will either report a *Complete* status (if all the instances have been received), *Incomplete* (if some instances are [still] missing) or *Inconsistent* if there is an error inside the numbering of the instances.
+