Cannot use Get-AzReservation with a Filter

[mcdonamw]

I'm trying to find a reservation by a specific name, but I'm getting errors about syntax within the Filter. I'm using a filter like any other powershell cmdlet so I'm not sure what's going on. For giggles I tried multiple other variations but all fail. I don't know if this is a me problem or something wrong with the cmdlet/API. Please advise.

PS C:\>Get-AzReservation -Filter {displayName -eq "rsv_e8-4asv4flex_q1_3yr_20231211_wus2"}
Get-AzReservation_List1: Expected '{' or '['. Was String: {"error":{"code":"BadRequest","message":"Request Uri Query Filter Parser error - Syntax error at position 13 in 'displayName -eq \"rsv_e8-4asv4flex_q1_3yr_20231211_wus2\"'."}}.

PS C:\>Get-AzReservation -Filter {displayName eq "rsv_e8-4asv4flex_q1_3yr_20231211_wus2"}
Get-AzReservation_List1: Expected '{' or '['. Was String: {"error":{"code":"BadRequest","message":"Request Uri Query Filter Parser error - Syntax error: character '\"' is not valid at position 15 in 'displayName eq \"rsv_e8-4asv4flex_q1_3yr_20231211_wus2\"'."}}.

PS C:\> Get-AzReservation -Filter "displayName eq rsv_e8-4asv4flex_q1_3yr_20231211_wus2"
Get-AzReservation_List1: Expected '{' or '['. Was String: {"error":{"code":"BadRequest","message":"Request Uri Query Filter Parser error - Syntax error at position 23 in 'displayName eq rsv_e8-4asv4flex_q1_3yr_20231211_wus2'."}}.

[mcdonamw]

I found my own answer, however I don't understand this.

In looking at the documentation for the Az bash commands, I saw a reference to a property that included more information than what I'm using. I tried following the same format and it works.

Get-AzReservation -Filter "properties/displayName eq 'rsv_e8-4asv4flex_q1_3yr_20231211_wus2'"

Why is all this extra information required? Other powershell cmdlets simply reference the properties that are returned.