diff --git a/docs/API.md b/docs/API.md
index bfa859c..64004fe 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -7,6 +7,11 @@ package. The snippets assume:
 import "sourcedock.dev/petrbalvin/interpres"
 ```
 
+The parser accepts TOML 1.0 documents plus the TOML 1.1 extensions: date-times
+and times without seconds, the `\e` and `\xHH` escape sequences, and
+multi-line inline tables with comments and trailing commas. The encoder emits
+TOML 1.0, which is valid under both versions.
+
 ## Functions
 
 ### `func Parse(data []byte) (map[string]any, error)`
@@ -139,8 +144,10 @@ offending key or index, for example `p: interpres: integer 300 overflows uint8`.
 Offset date-times decode into `time.Time` and keep their offset. The local
 variants decode into `LocalDateTime`, `LocalDate` and `LocalTime`, whose
 embedded `time.Time` is normalised to UTC (midnight UTC for a local date, the
-zero date for a local time). There is no implicit conversion between the offset
-and local kinds; assigning one to the other is an error.
+zero date for a local time). Every kind may omit the seconds as of TOML 1.1
+(`07:32`, `1979-05-27T07:32`); such a value carries a zero second, and the
+canonical rendering writes full seconds. There is no implicit conversion
+between the offset and local kinds; assigning one to the other is an error.
 
 ### Arrays of tables