diff --git a/README.md b/README.md
index 5c4122d..9798ed0 100644
--- a/README.md
+++ b/README.md
@@ -6,13 +6,18 @@ A  ICS / ICal parser and serialiser for Golang.
 Because the other libraries didn't quite do what I needed.
 
 Usage, parsing:
-```
+```golang
     cal, err := ParseCalendar(strings.NewReader(input))
 
 ```
 
-Creating:
+Usage, parsing from a URL :
+```golang
+    cal, err := ParseCalendar("an-ics-url")
 ```
+
+Creating:
+```golang
   cal := ics.NewCalendar()
   cal.SetMethod(ics.MethodRequest)
   event := cal.AddEvent(fmt.Sprintf("id@domain", p.SessionKey.IntID()))
diff --git a/calendar.go b/calendar.go
index ce4deb7..57bd14f 100644
--- a/calendar.go
+++ b/calendar.go
@@ -3,9 +3,12 @@ package ics
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"io"
+	"net/http"
+	"reflect"
 	"time"
 )
 
@@ -61,9 +64,111 @@ const (
 	ComponentPropertyTzid            = ComponentProperty(PropertyTzid)
 	ComponentPropertyComment         = ComponentProperty(PropertyComment)
 	ComponentPropertyRelatedTo       = ComponentProperty(PropertyRelatedTo)
+	ComponentPropertyMethod          = ComponentProperty(PropertyMethod)
+	ComponentPropertyRecurrenceId    = ComponentProperty(PropertyRecurrenceId)
 	ComponentPropertyDuration        = ComponentProperty(PropertyDuration)
+	ComponentPropertyContact         = ComponentProperty(PropertyContact)
+	ComponentPropertyRequestStatus   = ComponentProperty(PropertyRequestStatus)
+	ComponentPropertyRDate           = ComponentProperty(PropertyRdate)
 )
 
+// Required returns the rules from the RFC as to if they are required or not for any particular component type
+// If unspecified or incomplete, it returns false. -- This list is incomplete verify source. Happy to take PRs with reference
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Required(c Component) bool {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyDtstamp, ComponentPropertyUniqueId:
+		switch c.(type) {
+		case *VEvent:
+			return true
+		}
+	case ComponentPropertyDtStart:
+		switch c := c.(type) {
+		case *VEvent:
+			return !c.HasProperty(ComponentPropertyMethod)
+		}
+	}
+	return false
+}
+
+// Exclusive returns the ComponentProperty's using the rules from the RFC as to if one or more existing properties are prohibiting this one
+// If unspecified or incomplete, it returns false. -- This list is incomplete verify source. Happy to take PRs with reference
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Exclusive(c Component) []ComponentProperty {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyDtEnd:
+		switch c := c.(type) {
+		case *VEvent:
+			if c.HasProperty(ComponentPropertyDuration) {
+				return []ComponentProperty{ComponentPropertyDuration}
+			}
+		}
+	case ComponentPropertyDuration:
+		switch c := c.(type) {
+		case *VEvent:
+			if c.HasProperty(ComponentPropertyDtEnd) {
+				return []ComponentProperty{ComponentPropertyDtEnd}
+			}
+		}
+	}
+	return nil
+}
+
+// Singular returns the rules from the RFC as to if the spec states that if "Must not occur more than once"
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Singular(c Component) bool {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyClass, ComponentPropertyCreated, ComponentPropertyDescription, ComponentPropertyGeo,
+		ComponentPropertyLastModified, ComponentPropertyLocation, ComponentPropertyOrganizer, ComponentPropertyPriority,
+		ComponentPropertySequence, ComponentPropertyStatus, ComponentPropertySummary, ComponentPropertyTransp,
+		ComponentPropertyUrl, ComponentPropertyRecurrenceId:
+		switch c.(type) {
+		case *VEvent:
+			return true
+		}
+	}
+	return false
+}
+
+// Optional returns the rules from the RFC as to if the spec states that if these are optional
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Optional(c Component) bool {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyClass, ComponentPropertyCreated, ComponentPropertyDescription, ComponentPropertyGeo,
+		ComponentPropertyLastModified, ComponentPropertyLocation, ComponentPropertyOrganizer, ComponentPropertyPriority,
+		ComponentPropertySequence, ComponentPropertyStatus, ComponentPropertySummary, ComponentPropertyTransp,
+		ComponentPropertyUrl, ComponentPropertyRecurrenceId, ComponentPropertyRrule, ComponentPropertyAttach,
+		ComponentPropertyAttendee, ComponentPropertyCategories, ComponentPropertyComment,
+		ComponentPropertyContact, ComponentPropertyExdate, ComponentPropertyRequestStatus, ComponentPropertyRelatedTo,
+		ComponentPropertyResources, ComponentPropertyRDate:
+		switch c.(type) {
+		case *VEvent:
+			return true
+		}
+	}
+	return false
+}
+
+// Multiple returns the rules from the RFC as to if the spec states explicitly if multiple are allowed
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Multiple(c Component) bool {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyAttach, ComponentPropertyAttendee, ComponentPropertyCategories, ComponentPropertyComment,
+		ComponentPropertyContact, ComponentPropertyExdate, ComponentPropertyRequestStatus, ComponentPropertyRelatedTo,
+		ComponentPropertyResources, ComponentPropertyRDate:
+		switch c.(type) {
+		case *VEvent:
+			return true
+		}
+	}
+	return false
+}
+
 type Property string
 
 const (
@@ -413,6 +518,108 @@ func (cal *Calendar) setProperty(property Property, value string, params ...Prop
 	cal.CalendarProperties = append(cal.CalendarProperties, r)
 }
 
+func (calendar *Calendar) AddEvent(id string) *VEvent {
+	e := NewEvent(id)
+	calendar.Components = append(calendar.Components, e)
+	return e
+}
+
+func (calendar *Calendar) AddVEvent(e *VEvent) {
+	calendar.Components = append(calendar.Components, e)
+}
+
+func (calendar *Calendar) Events() (r []*VEvent) {
+	r = []*VEvent{}
+	for i := range calendar.Components {
+		switch event := calendar.Components[i].(type) {
+		case *VEvent:
+			r = append(r, event)
+		}
+	}
+	return
+}
+
+func (calendar *Calendar) RemoveEvent(id string) {
+	for i := range calendar.Components {
+		switch event := calendar.Components[i].(type) {
+		case *VEvent:
+			if event.Id() == id {
+				if len(calendar.Components) > i+1 {
+					calendar.Components = append(calendar.Components[:i], calendar.Components[i+1:]...)
+				} else {
+					calendar.Components = calendar.Components[:i]
+				}
+				return
+			}
+		}
+	}
+}
+
+func WithCustomClient(client *http.Client) *http.Client {
+	return client
+}
+
+func WithCustomRequest(request *http.Request) *http.Request {
+	return request
+}
+
+func ParseCalendarFromUrl(url string, opts ...any) (*Calendar, error) {
+	var ctx context.Context
+	var req *http.Request
+	var client HttpClientLike = http.DefaultClient
+	for opti, opt := range opts {
+		switch opt := opt.(type) {
+		case *http.Client:
+			client = opt
+		case HttpClientLike:
+			client = opt
+		case func() *http.Client:
+			client = opt()
+		case *http.Request:
+			req = opt
+		case func() *http.Request:
+			req = opt()
+		case context.Context:
+			ctx = opt
+		case func() context.Context:
+			ctx = opt()
+		default:
+			return nil, fmt.Errorf("unknown optional argument %d on ParseCalendarFromUrl: %s", opti, reflect.TypeOf(opt))
+		}
+	}
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if req == nil {
+		var err error
+		req, err = http.NewRequestWithContext(ctx, "GET", url, nil)
+		if err != nil {
+			return nil, fmt.Errorf("creating http request: %w", err)
+		}
+	}
+	return parseCalendarFromHttpRequest(client, req)
+}
+
+type HttpClientLike interface {
+	Do(req *http.Request) (*http.Response, error)
+}
+
+func parseCalendarFromHttpRequest(client HttpClientLike, request *http.Request) (*Calendar, error) {
+	resp, err := client.Do(request)
+	if err != nil {
+		return nil, fmt.Errorf("http request: %w", err)
+	}
+	defer func(closer io.ReadCloser) {
+		if derr := closer.Close(); derr != nil && err == nil {
+			err = fmt.Errorf("http request close: %w", derr)
+		}
+	}(resp.Body)
+	var cal *Calendar
+	cal, err = ParseCalendar(resp.Body)
+	// This allows the defer func to change the error
+	return cal, err
+}
+
 func ParseCalendar(r io.Reader) (*Calendar, error) {
 	state := "begin"
 	c := &Calendar{}
diff --git a/calendar_test.go b/calendar_test.go
index 38cad85..6ddd606 100644
--- a/calendar_test.go
+++ b/calendar_test.go
@@ -1,7 +1,10 @@
 package ics
 
 import (
+	"bytes"
+	_ "embed"
 	"io"
+	"net/http"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -410,3 +413,33 @@ func TestIssue52(t *testing.T) {
 		t.Fatalf("cannot read test directory: %v", err)
 	}
 }
+
+type MockHttpClient struct {
+	Response *http.Response
+	Error    error
+}
+
+func (m *MockHttpClient) Do(req *http.Request) (*http.Response, error) {
+	return m.Response, m.Error
+}
+
+var (
+	_ HttpClientLike = &MockHttpClient{}
+	//go:embed "testdata/rfc5545sec4/input1.ics"
+	input1TestData []byte
+)
+
+func TestIssue77(t *testing.T) {
+	url := "https://proseconsult.umontpellier.fr/jsp/custom/modules/plannings/direct_cal.jsp?data=58c99062bab31d256bee14356aca3f2423c0f022cb9660eba051b2653be722c4c7f281e4e3ad06b85d3374100ac416a4dc5c094f7d1a811b903031bde802c7f50e0bd1077f9461bed8f9a32b516a3c63525f110c026ed6da86f487dd451ca812c1c60bb40b1502b6511435cf9908feb2166c54e36382c1aa3eb0ff5cb8980cdb,1"
+
+	_, err := ParseCalendarFromUrl(url, &MockHttpClient{
+		Response: &http.Response{
+			StatusCode: 200,
+			Body:       io.NopCloser(bytes.NewReader(input1TestData)),
+		},
+	})
+
+	if err != nil {
+		t.Fatalf("Error reading file: %s", err)
+	}
+}
diff --git a/components.go b/components.go
index 8cc6e09..8f7c637 100644
--- a/components.go
+++ b/components.go
@@ -62,6 +62,8 @@ func NewComponent(uniqueId string) ComponentBase {
 	}
 }
 
+// GetProperty returns the first match for the particular property you're after. Please consider using:
+// ComponentProperty.Required to determine if GetProperty or GetProperties is more appropriate.
 func (cb *ComponentBase) GetProperty(componentProperty ComponentProperty) *IANAProperty {
 	for i := range cb.Properties {
 		if cb.Properties[i].IANAToken == string(componentProperty) {
@@ -71,6 +73,31 @@ func (cb *ComponentBase) GetProperty(componentProperty ComponentProperty) *IANAP
 	return nil
 }
 
+// GetProperties returns all matches for the particular property you're after. Please consider using:
+// ComponentProperty.Singular/ComponentProperty.Multiple to determine if GetProperty or GetProperties is more appropriate.
+func (cb *ComponentBase) GetProperties(componentProperty ComponentProperty) []*IANAProperty {
+	var result []*IANAProperty
+	for i := range cb.Properties {
+		if cb.Properties[i].IANAToken == string(componentProperty) {
+			result = append(result, &cb.Properties[i])
+		}
+	}
+	return result
+}
+
+// HasProperty returns true if a component property is in the component.
+func (cb *ComponentBase) HasProperty(componentProperty ComponentProperty) bool {
+	for i := range cb.Properties {
+		if cb.Properties[i].IANAToken == string(componentProperty) {
+			return true
+		}
+	}
+	return false
+}
+
+// SetProperty replaces the first match for the particular property you're setting, otherwise adds it. Please consider using:
+// ComponentProperty.Singular/ComponentProperty.Multiple to determine if AddProperty, SetProperty or ReplaceProperty is
+// more appropriate.
 func (cb *ComponentBase) SetProperty(property ComponentProperty, value string, params ...PropertyParameter) {
 	for i := range cb.Properties {
 		if cb.Properties[i].IANAToken == string(property) {
@@ -86,6 +113,17 @@ func (cb *ComponentBase) SetProperty(property ComponentProperty, value string, p
 	cb.AddProperty(property, value, params...)
 }
 
+// ReplaceProperty replaces all matches of the particular property you're setting, otherwise adds it. Returns a slice
+// of removed properties. Please consider using:
+// ComponentProperty.Singular/ComponentProperty.Multiple to determine if AddProperty, SetProperty or ReplaceProperty is
+// more appropriate.
+func (cb *ComponentBase) ReplaceProperty(property ComponentProperty, value string, params ...PropertyParameter) []IANAProperty {
+	removed := cb.RemoveProperty(property)
+	cb.AddProperty(property, value, params...)
+	return removed
+}
+
+// AddProperty appends a property
 func (cb *ComponentBase) AddProperty(property ComponentProperty, value string, params ...PropertyParameter) {
 	r := IANAProperty{
 		BaseProperty{
@@ -101,16 +139,44 @@ func (cb *ComponentBase) AddProperty(property ComponentProperty, value string, p
 	cb.Properties = append(cb.Properties, r)
 }
 
-// RemoveProperty removes from the component all properties that has
-// the name passed in removeProp.
-func (cb *ComponentBase) RemoveProperty(removeProp ComponentProperty) {
+// RemoveProperty removes from the component all properties that is of a particular property type, returning an slice of
+// removed entities
+func (cb *ComponentBase) RemoveProperty(removeProp ComponentProperty) []IANAProperty {
 	var keptProperties []IANAProperty
+	var removedProperties []IANAProperty
 	for i := range cb.Properties {
 		if cb.Properties[i].IANAToken != string(removeProp) {
 			keptProperties = append(keptProperties, cb.Properties[i])
+		} else {
+			removedProperties = append(removedProperties, cb.Properties[i])
+		}
+	}
+	cb.Properties = keptProperties
+	return removedProperties
+}
+
+// RemovePropertyByValue removes from the component all properties that has a particular property type and value,
+// return a count of removed properties
+func (cb *ComponentBase) RemovePropertyByValue(removeProp ComponentProperty, value string) []IANAProperty {
+	return cb.RemovePropertyByFunc(removeProp, func(p IANAProperty) bool {
+		return p.Value == value
+	})
+}
+
+// RemovePropertyByFunc removes from the component all properties that has a particular property type and the function
+// remove returns true for
+func (cb *ComponentBase) RemovePropertyByFunc(removeProp ComponentProperty, remove func(p IANAProperty) bool) []IANAProperty {
+	var keptProperties []IANAProperty
+	var removedProperties []IANAProperty
+	for i := range cb.Properties {
+		if cb.Properties[i].IANAToken != string(removeProp) && remove(cb.Properties[i]) {
+			keptProperties = append(keptProperties, cb.Properties[i])
+		} else {
+			removedProperties = append(removedProperties, cb.Properties[i])
 		}
 	}
 	cb.Properties = keptProperties
+	return removedProperties
 }
 
 const (
@@ -480,13 +546,13 @@ type VEvent struct {
 	ComponentBase
 }
 
-func (c *VEvent) SerializeTo(w io.Writer) {
-	c.ComponentBase.serializeThis(w, "VEVENT")
+func (event *VEvent) SerializeTo(w io.Writer) {
+	event.ComponentBase.serializeThis(w, "VEVENT")
 }
 
-func (c *VEvent) Serialize() string {
+func (event *VEvent) Serialize() string {
 	b := &bytes.Buffer{}
-	c.ComponentBase.serializeThis(b, "VEVENT")
+	event.ComponentBase.serializeThis(b, "VEVENT")
 	return b.String()
 }
 
@@ -497,77 +563,40 @@ func NewEvent(uniqueId string) *VEvent {
 	return e
 }
 
-func (cal *Calendar) AddEvent(id string) *VEvent {
-	e := NewEvent(id)
-	cal.Components = append(cal.Components, e)
-	return e
+func (event *VEvent) SetEndAt(t time.Time, props ...PropertyParameter) {
+	event.SetProperty(ComponentPropertyDtEnd, t.UTC().Format(icalTimestampFormatUtc), props...)
 }
 
-func (cal *Calendar) AddVEvent(e *VEvent) {
-	cal.Components = append(cal.Components, e)
+func (event *VEvent) SetLastModifiedAt(t time.Time, props ...PropertyParameter) {
+	event.SetProperty(ComponentPropertyLastModified, t.UTC().Format(icalTimestampFormatUtc), props...)
 }
 
-func (cal *Calendar) RemoveEvent(id string) {
-	for i := range cal.Components {
-		switch event := cal.Components[i].(type) {
-		case *VEvent:
-			if event.Id() == id {
-				if len(cal.Components) > i+1 {
-					cal.Components = append(cal.Components[:i], cal.Components[i+1:]...)
-				} else {
-					cal.Components = cal.Components[:i]
-				}
-				return
-			}
-		}
-	}
+func (event *VEvent) SetGeo(lat interface{}, lng interface{}, params ...PropertyParameter) {
+	event.setGeo(lat, lng, params...)
 }
 
-func (cal *Calendar) Events() []*VEvent {
-	var r []*VEvent
-	for i := range cal.Components {
-		switch event := cal.Components[i].(type) {
-		case *VEvent:
-			r = append(r, event)
-		}
-	}
-	return r
+func (event *VEvent) SetPriority(p int, params ...PropertyParameter) {
+	event.setPriority(p, params...)
 }
 
-func (c *VEvent) SetEndAt(t time.Time, params ...PropertyParameter) {
-	c.SetProperty(ComponentPropertyDtEnd, t.UTC().Format(icalTimestampFormatUtc), params...)
+func (event *VEvent) SetResources(r string, params ...PropertyParameter) {
+	event.setResources(r, params...)
 }
 
-func (c *VEvent) SetLastModifiedAt(t time.Time, params ...PropertyParameter) {
-	c.SetProperty(ComponentPropertyLastModified, t.UTC().Format(icalTimestampFormatUtc), params...)
+func (event *VEvent) AddAlarm() *VAlarm {
+	return event.addAlarm()
 }
 
-func (c *VEvent) SetGeo(lat interface{}, lng interface{}, params ...PropertyParameter) {
-	c.setGeo(lat, lng, params...)
+func (event *VEvent) AddVAlarm(a *VAlarm) {
+	event.addVAlarm(a)
 }
 
-func (c *VEvent) SetPriority(p int, params ...PropertyParameter) {
-	c.setPriority(p, params...)
-}
-
-func (c *VEvent) SetResources(r string, params ...PropertyParameter) {
-	c.setResources(r, params...)
-}
-
-func (c *VEvent) AddAlarm() *VAlarm {
-	return c.addAlarm()
-}
-
-func (c *VEvent) AddVAlarm(a *VAlarm) {
-	c.addVAlarm(a)
-}
-
-func (c *VEvent) Alarms() []*VAlarm {
-	return c.alarms()
+func (event *VEvent) Alarms() []*VAlarm {
+	return event.alarms()
 }
 
-func (c *VEvent) GetAllDayEndAt() (time.Time, error) {
-	return c.getTimeProp(ComponentPropertyDtEnd, true)
+func (event *VEvent) GetAllDayEndAt() (time.Time, error) {
+	return event.getTimeProp(ComponentPropertyDtEnd, true)
 }
 
 type TimeTransparency string
@@ -577,8 +606,8 @@ const (
 	TransparencyTransparent TimeTransparency = "TRANSPARENT"
 )
 
-func (c *VEvent) SetTimeTransparency(v TimeTransparency, params ...PropertyParameter) {
-	c.SetProperty(ComponentPropertyTransp, string(v), params...)
+func (event *VEvent) SetTimeTransparency(v TimeTransparency, params ...PropertyParameter) {
+	event.SetProperty(ComponentPropertyTransp, string(v), params...)
 }
 
 type VTodo struct {