diff --git a/src/fr24sdk/models/__init__.py b/src/fr24sdk/models/__init__.py
index 9130935..cf0def1 100644
--- a/src/fr24sdk/models/__init__.py
+++ b/src/fr24sdk/models/__init__.py
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: MIT
 """Exposes data models for the Flightradar24 SDK."""
 
+from .flight_category import FlightCategory
 from .airline import AirlineLight
 from .airport import AirportFull, AirportLight, Country, Timezone
 from .flight import (
@@ -27,6 +28,7 @@
 
 __all__ = [
     "AirlineLight",
+    "FlightCategory",
     "AirportFull",
     "AirportLight",
     "Country",
diff --git a/src/fr24sdk/models/flight_category.py b/src/fr24sdk/models/flight_category.py
new file mode 100644
index 0000000..0879d60
--- /dev/null
+++ b/src/fr24sdk/models/flight_category.py
@@ -0,0 +1,30 @@
+# SPDX-FileCopyrightText: Copyright Flightradar24
+#
+# SPDX-License-Identifier: MIT
+"""Flight category enumeration for the Flightradar24 SDK."""
+
+from enum import Enum
+
+
+class FlightCategory(str, Enum):
+    """Enumeration of FlightRadar24 flight categories.
+    
+    Maps character literals used by the FR24 API to identify different
+    types of aircraft and flight operations.
+    """
+    
+    PASSENGER = "P"
+    CARGO = "C"
+    MILITARY_AND_GOVERNMENT = "M"
+    BUSINESS_JETS = "J"
+    GENERAL_AVIATION = "T"
+    HELICOPTERS = "H"
+    LIGHTER_THAN_AIR = "B"
+    GLIDERS = "G"
+    DRONES = "D"
+    GROUND_VEHICLES = "V"
+    OTHER = "O"
+    NON_CATEGORIZED = "N"
+
+    def __str__(self) -> str:
+        return self.value
diff --git a/src/fr24sdk/resources/historic/positions.py b/src/fr24sdk/resources/historic/positions.py
index 36d4f66..c648590 100644
--- a/src/fr24sdk/resources/historic/positions.py
+++ b/src/fr24sdk/resources/historic/positions.py
@@ -23,6 +23,7 @@
     Boundary,
     AltitudeRange,
 )
+from ...models.flight_category import FlightCategory
 from ...models.regex_patterns import (
     FLIGHT_NUMBER_PATTERN,
     CALLSIGN_PATTERN,
@@ -73,7 +74,7 @@ class _HistoricPositionsParams(BaseModel):
         list[Annotated[str, StringConstraints(pattern=SQUAWK_PATTERN)]]
     ] = Field(default=None, max_length=15)
     categories: Optional[
-        list[Annotated[str, StringConstraints(pattern=SERVICE_TYPES_PATTERN)]]
+        list[Union[FlightCategory, Annotated[str, StringConstraints(pattern=SERVICE_TYPES_PATTERN)]]]
     ] = Field(default=None, max_length=15)
     data_sources: Optional[
         list[Annotated[str, StringConstraints(pattern=DATA_SOURCE_PATTERN)]]
@@ -136,7 +137,7 @@ def get_light(
         aircraft: Optional[str] = None,
         altitude_ranges: Optional[list[Union[AltitudeRange, str]]] = None,
         squawks: Optional[list[str]] = None,
-        categories: Optional[list[str]] = None,
+        categories: Optional[list[Union[FlightCategory, str]]] = None,
         data_sources: Optional[list[str]] = None,
         gspeed: Optional[Union[int, str]] = None,
         limit: Optional[int] = None,
@@ -183,7 +184,7 @@ def get_full(
         aircraft: Optional[str] = None,
         altitude_ranges: Optional[list[Union[AltitudeRange, str]]] = None,
         squawks: Optional[list[str]] = None,
-        categories: Optional[list[str]] = None,
+        categories: Optional[list[Union[FlightCategory, str]]] = None,
         data_sources: Optional[list[str]] = None,
         gspeed: Optional[Union[int, str]] = None,
         limit: Optional[int] = None,
@@ -230,7 +231,7 @@ def count(
         aircraft: Optional[str] = None,
         altitude_ranges: Optional[list[Union[AltitudeRange, str]]] = None,
         squawks: Optional[list[str]] = None,
-        categories: Optional[list[str]] = None,
+        categories: Optional[list[Union[FlightCategory, str]]] = None,
         data_sources: Optional[list[str]] = None,
         gspeed: Optional[Union[int, str]] = None,
     ) -> CountResponse:
diff --git a/src/fr24sdk/resources/live/positions.py b/src/fr24sdk/resources/live/positions.py
index 9588316..b29e061 100644
--- a/src/fr24sdk/resources/live/positions.py
+++ b/src/fr24sdk/resources/live/positions.py
@@ -17,6 +17,7 @@
     FlightPositionsFullResponse,
     CountResponse,
 )
+from ...models.flight_category import FlightCategory
 from ...models.geographic import (
     Boundary,
     AltitudeRange,
@@ -67,7 +68,7 @@ class _LivePositionsParams(BaseModel):
         list[Annotated[str, StringConstraints(pattern=SQUAWK_PATTERN)]]
     ] = Field(default=None, max_length=15)
     categories: Optional[
-        list[Annotated[str, StringConstraints(pattern=SERVICE_TYPES_PATTERN)]]
+        list[Union[FlightCategory, Annotated[str, StringConstraints(pattern=SERVICE_TYPES_PATTERN)]]]
     ] = Field(default=None, max_length=15)
     data_sources: Optional[
         list[Annotated[str, StringConstraints(pattern=DATA_SOURCE_PATTERN)]]
@@ -111,7 +112,7 @@ def get_light(
         aircraft: Optional[str] = None,
         altitude_ranges: Optional[list[Union[AltitudeRange, str]]] = None,
         squawks: Optional[list[str]] = None,
-        categories: Optional[list[str]] = None,
+        categories: Optional[list[Union[FlightCategory, str]]] = None,
         data_sources: Optional[list[str]] = None,
         airspaces: Optional[list[str]] = None,
         gspeed: Optional[Union[int, str]] = None,
@@ -156,7 +157,7 @@ def get_full(
         aircraft: Optional[str] = None,
         altitude_ranges: Optional[list[Union[AltitudeRange, str]]] = None,
         squawks: Optional[list[str]] = None,
-        categories: Optional[list[str]] = None,
+        categories: Optional[list[Union[FlightCategory, str]]] = None,
         data_sources: Optional[list[str]] = None,
         airspaces: Optional[list[str]] = None,
         gspeed: Optional[Union[int, str]] = None,
@@ -201,7 +202,7 @@ def count(
         aircraft: Optional[str] = None,
         altitude_ranges: Optional[list[Union[AltitudeRange, str]]] = None,
         squawks: Optional[list[str]] = None,
-        categories: Optional[list[str]] = None,
+        categories: Optional[list[Union[FlightCategory, str]]] = None,
         data_sources: Optional[list[str]] = None,
         gspeed: Optional[Union[int, str]] = None,
     ) -> CountResponse: