There are a few rare STR formats that could be found in the game's files, but I haven't seen anyone mention them anywhere. I pulled all of these from the objects.package:
1- STR Format: Zero
Spec:
Name: 64 bytes
Null/Format Code?: 2 bytes
Resources
endtable1 skill table
Type: 0x53545223, Group: 0x7FAB08F6, Instance: 0x00000081, Resource: 0x00000000
Nightstand Expensive skill table
Type: 0x53545223, Group: 0x7F280D6D, Instance: 0x00000081, Resource: 0x00000000
bedstandex attribute labels
Type: 0x53545223, Group: 0x7F280D6D, Instance: 0x00000100, Resource: 0x00000000
2- STR Format: No Format
Spec:
Name: 64 bytes
Null/Format Code?: 1 byte integer
Count: 1 byte integer
Loop Count times:
Length: 1 byte integer
Value: String with length Length
Resources
Behavior editor string set
Type: 0x53545223, Group: 0x7F6D880B, Instance: 0x0000012C, Resource: 0x00000000
Behavior editor string set
Type: 0x53545223, Group: 0x7FBD8997, Instance: 0x0000012C, Resource: 0x00000000
3- STR Format: 0xFFF6
This is a weird format with some weird dividers between the strings, even SimPE won't read it, and I couldn't figure it out the last time I tried. Here is the resources with this format if anyone wants to try to figure them out:
Resources
Suit primitive strings
Type: 0x53545223, Group: 0x7F3D258A, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7FE94D58, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F27193D, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F24F935, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F83D9EC, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F2CAB90, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7FBEBDFE, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7FFAA5E5, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F234024, Instance: 0x00000130, Resource: 0x00000000
4- STR Format: 0xFFFD
Already known.
5- STR Format: 0xFFFE
Spec:
Name: 64 bits
Format Code: 2 bytes integer
Count: 2 bytes integer
Loop Count Times:
Value: Null-terminated String
Null: 1 byte (Description string?)
Resources
Relationships
Type: 0x53545223, Group: 0x7F6D880B, Instance: 0x00000102, Resource: 0x00000000
relationship labels
Type: 0x53545223, Group: 0x7F17187C, Instance: 0x00000102, Resource: 0x00000000
PedPortal relationship labels
Type: 0x53545223, Group: 0x7F19EC55, Instance: 0x00000102, Resource: 0x00000000
Mail Box relationship labels
Type: 0x53545223, Group: 0x7FE4B434, Instance: 0x00000102, Resource: 0x00000000
Relationships
Type: 0x53545223, Group: 0x7FBD8997, Instance: 0x00000102, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F979D47, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7FE9B3DE, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F8ECBFD, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F79C748, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F1FF01F, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F9E24A1, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7FFCB26D, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F1E9307, Instance: 0x00000130, Resource: 0x00000000
Suit primitive strings
Type: 0x53545223, Group: 0x7F694047, Instance: 0x00000130, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7F979D47, Instance: 0x00001000, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7FE9B3DE, Instance: 0x00001000, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7F8ECBFD, Instance: 0x00001000, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7F79C748, Instance: 0x00001000, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7F1FF01F, Instance: 0x00001000, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7F9E24A1, Instance: 0x00001000, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7FFCB26D, Instance: 0x00001000, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7F1E9307, Instance: 0x00001000, Resource: 0x00000000
named trees
Type: 0x53545223, Group: 0x7F694047, Instance: 0x00001000, Resource: 0x00000000
skin colors
Type: 0x53545223, Group: 0x7F01EC29, Instance: 0x00002000, Resource: 0x00000000
6- STR Format: 0xFFFF
This is the same as format 0xFFFD, but STR entries that have this format are always empty/have no strings.
Spec:
Name: 64 bytes
Format Code: 2 bytes integer
Count: 2 bytes integer