Oh, wow. I never thought of using SlickEdit like that before. The list of "icons" that you're looking for are actually the various VS_TAGTYPEs. You can find them in tagsdb.sh. For the sake of convenience, this is the list out of version 14.0.2:
#define VS_TAGTYPE_proc 1 // procedure or command
#define VS_TAGTYPE_proto 2 // function prototype
#define VS_TAGTYPE_define 3 // preprocessor macro definition
#define VS_TAGTYPE_typedef 4 // type definition
#define VS_TAGTYPE_gvar 5 // global variable declaration
#define VS_TAGTYPE_struct 6 // structure definition
#define VS_TAGTYPE_enumc 7 // enumeration value
#define VS_TAGTYPE_enum 8 // enumerated type
#define VS_TAGTYPE_class 9 // class definition
#define VS_TAGTYPE_union 10 // structure / union definition
#define VS_TAGTYPE_label 11 // label
#define VS_TAGTYPE_interface 12 // interface, eg, for Java, IDL, or C#
#define VS_TAGTYPE_constructor 13 // class constructor
#define VS_TAGTYPE_destructor 14 // class destructor
#define VS_TAGTYPE_package 15 // package / module / namespace
#define VS_TAGTYPE_var 16 // member of a class / struct / package
#define VS_TAGTYPE_lvar 17 // local variable declaration
#define VS_TAGTYPE_constant 18 // pascal constant
#define VS_TAGTYPE_function 19 // function
#define VS_TAGTYPE_property 20 // property
#define VS_TAGTYPE_program 21 // pascal program
#define VS_TAGTYPE_library 22 // pascal library
#define VS_TAGTYPE_parameter 23 // function or procedure parameter
#define VS_TAGTYPE_import 24 // package import or using
#define VS_TAGTYPE_friend 25 // C++ friend relationship
#define VS_TAGTYPE_database 26 // SQL/OO Database
#define VS_TAGTYPE_table 27 // Database Table
#define VS_TAGTYPE_column 28 // Database Column
#define VS_TAGTYPE_index 29 // Database index
#define VS_TAGTYPE_view 30 // Database view
#define VS_TAGTYPE_trigger 31 // Database trigger
#define VS_TAGTYPE_form 32 // GUI Form or window
#define VS_TAGTYPE_menu 33 // GUI Menu
#define VS_TAGTYPE_control 34 // GUI Control or Widget
#define VS_TAGTYPE_eventtab 35 // GUI Event table
#define VS_TAGTYPE_procproto 36 // Prototype for procedure
#define VS_TAGTYPE_task 37 // Ada task
#define VS_TAGTYPE_include 38 // C++ include or Ada with (dependency)
#define VS_TAGTYPE_file 39 // COBOL file descriptor
#define VS_TAGTYPE_group 40 // Container variable
#define VS_TAGTYPE_subfunc 41 // Nested function or cobol paragraph
#define VS_TAGTYPE_subproc 42 // Nested procedure or cobol paragraph
#define VS_TAGTYPE_cursor 43 // Database result set cursor
#define VS_TAGTYPE_tag 44 // SGML or XML tag type (like a class)
#define VS_TAGTYPE_taguse 45 // SGML or XML tag instance (like an object)
#define VS_TAGTYPE_statement 46 // generic statement
#define VS_TAGTYPE_annotype 47 // Java annotation type or C# attribute class
#define VS_TAGTYPE_annotation 48 // Java annotation or C# attribute instance
#define VS_TAGTYPE_call 49 // Function/Method call
#define VS_TAGTYPE_if 50 // If/Switch statement
#define VS_TAGTYPE_loop 51 // Loop statement
#define VS_TAGTYPE_break 52 // Break statement
#define VS_TAGTYPE_continue 53 // Continue statement
#define VS_TAGTYPE_return 54 // Return statement
#define VS_TAGTYPE_goto 55 // Goto statement
#define VS_TAGTYPE_try 56 // Try/Catch/Finally statement
#define VS_TAGTYPE_pp 57 // Preprocessing statement
#define VS_TAGTYPE_block 58 // Statement block
#define VS_TAGTYPE_mixin 59 // D language mixin construct
#define VS_TAGTYPE_target 60 // Ant target type
It looks like you just want the last part of the type.