diff --git a/src/components.rs b/src/components.rs
index e81deb2..8e61e76 100644
--- a/src/components.rs
+++ b/src/components.rs
@@ -433,9 +433,10 @@ mod tests {
         let event = Event::new().url(url).done();
 
         let serialized = event.to_string();
-        let reparsed =
-            dbg!(Other::try_from(crate::parser::Component::<'_>::try_from(serialized.as_str()).unwrap())
-                .unwrap());
+        let reparsed = dbg!(Other::try_from(
+            crate::parser::Component::<'_>::try_from(serialized.as_str()).unwrap()
+        )
+        .unwrap());
 
         assert_eq!(event.get_url(), Some(url));
         assert_eq!(reparsed.get_url(), Some(url));
diff --git a/src/parser/utils.rs b/src/parser/utils.rs
index c019fbf..3975c67 100644
--- a/src/parser/utils.rs
+++ b/src/parser/utils.rs
@@ -12,6 +12,99 @@ use pretty_assertions::assert_eq;
 
 use super::parsed_string::ParseString;
 
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+enum ValueType {
+    /// [RFC 5545 3.3.1](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.1)
+    Binary,
+    /// [RFC 5545 3.3.2](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.2)
+    Boolean,
+    /// [RFC 5545 3.3.3](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.3)
+    CalAddress,
+    /// [RFC 5545 3.3.4](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.4)
+    Date,
+    /// [RFC 5545 3.3.5](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.5)
+    DateTime,
+    /// [RFC 5545 3.3.6](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.6)
+    Duration,
+    /// [RFC 5545 3.3.7](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.7)
+    Float,
+    /// [RFC 5545 3.3.8](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.8)
+    Integer,
+    /// [RFC 5545 3.3.9](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.9)
+    Period,
+    /// [RFC 5545 3.3.10](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.10)
+    Recur,
+    /// [RFC 5545 3.3.11](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.11)
+    Text,
+    /// [RFC 5545 3.3.12](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.12)
+    Time,
+    /// [RFC 5545 3.3.13](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.13)
+    Uri,
+    /// [RFC 5545 3.3.14](https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.14)
+    UtcOffset,
+    Invalid
+}
+
+/// returns the proper value type for a given property according to RFC 5545
+fn value_type(property_name: &str) -> ValueType {
+    use ValueType::*;
+    if property_name.chars().any(|c| c.is_lowercase()) {
+        panic!("property_name must be uppercase");
+    }
+    match property_name {
+        "CALSCALE" => Text,
+        "METHOD"  => Text,
+        "PRODID" => Text,
+        "VERSION" => Text,
+        "ATTACH" => Uri, // or BINARY
+        "CATEGORIES" => Text,
+        "CLASS" => Text,
+        "COMMENT" => Text,
+        "DESCRIPTION" => Text,
+        "GEO" => Float,
+        "LOCATION" => Text,
+        "PERCENT-COMPLETE" => Integer,
+        "PRIORITY" => Integer,
+        "RESOURCES" => Text,
+        "STATUS" => Text,            // 3.8.1.11
+        "SUMMARY" => Text,           // 3.8.8.1.12
+        "COMPLETED" => DateTime,     // 3.8.2.1
+        "DTEND" => DateTime,         // or DATE // 3.8.2.2
+        "DUE" => DateTime,           // or DATE // 3.8.2.3
+        "DTSTART" => DateTime,       // or DATE 3.8.2.4
+        "DURATION" => Duration,      // 3.8.2.5
+        "FREEBUSY" => Period,        // 3.8.2.6
+        "TRANSP" => Text,            // 3.8.2.7
+        "TZID" => Text,              // 3.8.3.1
+        "TZNAME" => Text,            // 3.8.3.2
+        "TZOFFSETFROM" => UtcOffset, //
+        "TZOFFSETTO" => UtcOffset,   //
+        "TZURL" => Uri,              //
+        "ATTENDEE" => CalAddress,    // 3.8.4.1
+        "CONTACT" => Text,           // 3.8.4.2
+        "ORGANIZER" => CalAddress,   // 3.8.4.3
+        "RECURRENCE-ID" => DateTime, // 3.8.4.4
+        "RELATED-TO" => Text,        //
+        "URL" => Uri,                //
+        "UID" => Text,               //
+        "EXDATE" => DateTime,        // or DATE-TIME //
+        "RDATE" => DateTime,         // or PERIOD // or DATE-TIME // or DATE //
+        "RRULE" => Recur,            //
+        "ACTION" => Text,            //
+        "REPEAT" => Integer,         //
+        "TRIGGER" => Duration,       // or DATE-TIME (must be UTC) // 3.8.6.3
+        "CREATED" => DateTime,       // 3.8.7.1
+        "DTSTAMP" => DateTime,       //  3.8.7.2
+        "LAST-MODIFIED" => DateTime, // 3.8.7.3
+        "SEQUENCE" => Integer,       // 3.8.7.4
+        // 3.8.8.1
+        // "An IANA-registered property name" => Any parameter can be specified on this property.
+        "X-"/* ... */ => Text,       // any type 3.8.8.2
+        "REQUEST-STATUS" => Text, // 3.8.8.3
+        _ => Invalid,
+    }
+}
+
 // TODO: how do I express <<alpha_or_dash, but not "END">>
 pub fn property_key<'a, E: ParseError<&'a str> + ContextError<&'a str>>(
     input: &'a str,
diff --git a/src/properties.rs b/src/properties.rs
index 757eb62..1da596b 100644
--- a/src/properties.rs
+++ b/src/properties.rs
@@ -141,6 +141,8 @@ impl Property {
     }
 
     /// <https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.11>
+    /// TODO: this should not be used for properties but TEXT
+    #[allow(dead_code)]
     fn escape_text(input: &str) -> String {
         input
             .replace('\\', r#"\\"#)