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Boston Capital Tax Credit Fund IV LP – ‘10-Q’ for 9/30/19 – ‘EX-101.DEF’

On:  Wednesday, 11/13/19, at 9:36am ET   ·   For:  9/30/19   ·   Accession #:  913778-19-6   ·   File #:  0-26200

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  As Of               Filer                 Filing    For·On·As Docs:Size

11/13/19  Boston Cap Tax Credit Fund IV LP  10-Q        9/30/19   40:13M

Quarterly Report   —   Form 10-Q   —   Sect. 13 / 15(d) – SEA’34
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Bctc Iv Sept 2019 10-Q                              HTML   2.42M 
 2: EX-31       Bctc Iv Sept 2019 Certification 302                 HTML     17K 
 3: EX-31       Bctc Iv Sept 2019 Certification 302                 HTML     17K 
 4: EX-32       Bctc Iv Sept 2019 Certification 906                 HTML     15K 
 5: EX-32       Bctc Iv Sept 2019 Certification 906                 HTML     15K 
25: R1          Document And Entity Information                     HTML     42K 
34: R2          Condensed Balance Sheets                            HTML    234K 
30: R3          Condensed Balance Sheets (Parenthetical)            HTML    102K 
12: R4          Condensed Statements of Operations                  HTML    243K 
24: R5          Condensed Statements of Changes in Partners'        HTML     97K 
                Capital (Deficit)                                                
33: R6          Condensed Statements of Cash Flows                  HTML    293K 
29: R7          Organization                                        HTML    105K 
13: R8          Accounting and Financial Reporting Policies         HTML     17K 
23: R9          Related Party Transactions                          HTML    150K 
18: R10         Investments in Operating Partnerships               HTML   1.40M 
22: R11         Taxable Loss                                        HTML     15K 
40: R12         Income Taxes                                        HTML     16K 
28: R13         Subsequent Events                                   HTML     17K 
17: R14         Organization (Tables)                               HTML    100K 
21: R15         Related Party Transactions (Tables)                 HTML    150K 
39: R16         Investments in Operating Partnerships (Tables)      HTML   1.40M 
27: R17         ORGANIZATION - BACs sold and total equity           HTML     97K 
                (Details)                                                        
19: R18         ORGANIZATION - Additional Information (Details)     HTML     21K 
20: R19         RELATED PARTY TRANSACTIONS - Fund management fees   HTML     66K 
                accrued (Details)                                                
38: R20         RELATED PARTY TRANSACTIONS - Fund management fees   HTML     64K 
                paid (Details)                                                   
32: R21         RELATED PARTY TRANSACTIONS - Additional             HTML     15K 
                Information (Details)                                            
15: R22         INVESTMENTS IN OPERATING PARTNERSHIPS - Operating   HTML     63K 
                Partnerships within the Fund (Details)                           
26: R23         INVESTMENTS IN OPERATING PARTNERSHIPS -             HTML     38K 
                Contributions payable (Details)                                  
37: R24         INVESTMENTS IN OPERATING PARTNERSHIPS -             HTML     94K 
                Dispositions by series (Details)                                 
31: R25         INVESTMENTS IN OPERATING PARTNERSHIPS - Current     HTML    162K 
                financial results available for the Operating                    
                Partnerships (Details)                                           
14: R26         INVESTMENTS IN OPERATING PARTNERSHIPS - Additional  HTML     23K 
                Information (Details)                                            
35: XML         IDEA XML File -- Filing Summary                      XML     62K 
16: EXCEL       IDEA Workbook of Financial Reports                  XLSX     81K 
 6: EX-101.INS  XBRL Instance -- bctciv-20190930                     XML   7.20M 
 8: EX-101.CAL  XBRL Calculations -- bctciv-20190930_cal             XML     56K 
 9: EX-101.DEF  XBRL Definitions -- bctciv-20190930_def              XML    452K 
10: EX-101.LAB  XBRL Labels -- bctciv-20190930_lab                   XML    364K 
11: EX-101.PRE  XBRL Presentations -- bctciv-20190930_pre            XML    581K 
 7: EX-101.SCH  XBRL Schema -- bctciv-20190930                       XSD     96K 
36: ZIP         XBRL Zipped Folder -- 0000913778-19-000006-xbrl      Zip    172K 


‘EX-101.DEF’   —   XBRL Definitions — bctciv-20190930_def


This Exhibit is an XBRL XML File.


                                                                                                                                                                                
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