Adding README and naming changes

1 files changed, 28 insertions, 0 deletions

diff --git a/README.txt b/README.txt
new file mode 100644
index 0000000..f0cf0a9
--- /dev/null
+++ b/README.txt
@@ -0,0 +1,28 @@
+Cinisis database reader
+=======================
+
+Naming conventions
+------------------
+
+The following naming conventions are used through Cinisis aiming to help
+iterating over all the data from a ISIS database.
+
+  - Database:  an ISIS database.
+  - Entry:     a given MFN in the database.
+  - Value:     all the data from a given entry in the database.
+  - Field:     a numbered set of values from a given entry.
+  - Row:       a single value from a given field.
+  - Main item: the data in a row without a qualifier.
+  - Subfield:  every data in a row within a qualifier.
+  - Item:      either a main item or subfield withing a row.
+
+Example:
+
+  MFN 1 with entry
+  10: First  row of field 10^aWith a subfield^bAnd another one
+  10: Second row of field 10^bJust with the second subfield
+  20: This is the main item^yAnd this is another item
+
+For that entry we have fields 10 and 20, where field 10 has two rows (i.e, two
+repetitions). The main field is the data wich is has no qualifier (^) and a
+subfield is the data with qualifiers (like subfields a and b from above).