For some reasons, a margin is automatically added between <fo:static-content flow-name="xsl-region-before"> and <fo:flow flow-name="xsl-region-body" space-before="0pt" margin-top ="0pt" padding-top="0pt">.
How can I remove it?
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:fo="http://www.w3.org/1999/XSL/Format">
<xsl:template match="/">
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
<fo:layout-master-set>
<fo:simple-page-master master-name="A4" page-width="210mm" page-height="297mm" margin="10mm">
<fo:region-body margin-top="20mm" margin-bottom="20mm"/>
<fo:region-before extent="20mm"/>
<fo:region-after extent="20mm"/>
</fo:simple-page-master>
</fo:layout-master-set>
<fo:page-sequence master-reference="A4">
<fo:static-content flow-name="xsl-region-before">
<fo:block-container width="539.3px" height="20px" padding="0px" margin="0px" border-bottom="1pt solid black">
<fo:block>
<fo:inline font-family="arialBold" font-size="18px" font-weight="bold" color="#000000">
Задачи обработки отправлений
</fo:inline>
<fo:inline font-family="arial" font-size="8px" color="#000000">
Страница <fo:page-number/>/<fo:page-number-citation ref-id="end-of-doc"/>
</fo:inline>
<fo:leader leader-length="37px"/>
<fo:inline font-family="arial" font-size="18px" font-weight="bold" color="#000000">
<xsl:value-of select="AppealPrintFormList/currentDate"/> в <xsl:value-of select="AppealPrintFormList/currentTime"/>
</fo:inline>
</fo:block>
</fo:block-container>
</fo:static-content>
<fo:flow flow-name="xsl-region-body" space-before="0pt" margin-top="0pt" padding-top="0pt">
<xsl:for-each select="AppealPrintFormList/AppealPrintForm">
<fo:table table-layout="fixed" width="556px">
<fo:table-column column-width="91px"/>
<fo:table-column column-width="162px"/>
<fo:table-column column-width="37.5%"/>
<fo:table-body>
<fo:table-row>
<fo:table-cell padding="0px">
<fo:block font-family="arial" font-size="12px" font-weight="bold">
<xsl:value-of select="clientSystemOrderNumber"/>
</fo:block>
<fo:block font-family="arial" font-size="8px" color="#7F7F7F" font-weight="bold">
<xsl:value-of select="appealType"/>
</fo:block>
</fo:table-cell>
<fo:table-cell padding="0px">
<fo:block font-family="arial" font-size="8px" color="#000000">
Получ.: <xsl:value-of select="contactPhone"/>
</fo:block>
<fo:block font-family="arialBold" font-size="8px" color="#000000">
Отпр.: <xsl:value-of select="sender"/>
</fo:block>
</fo:table-cell>
<fo:table-cell padding="0px">
<fo:block-container margin-left="12.5px" padding="0px" text-align="left" start-indent="0px" end-indent="0px">
<fo:block margin="0px" padding="0px">
<fo:inline font-family="arialBold" font-weight="bold" font-size="8px" color="#000000">
<xsl:value-of select="barcode"/>
</fo:inline>
<fo:leader leader-length="6px"/>
<fo:inline font-family="arial" font-size="8px" color="#000000">
<xsl:value-of select="ukdRegisterWeight"/> кг
</fo:inline>
<fo:leader leader-length="4px"/>
<fo:inline font-family="arial" font-size="8px" color="#000000">
<xsl:value-of select="routeName"/>
</fo:inline>
</fo:block>
<fo:block margin="0px" padding="0px">
<fo:inline font-family="arialBold" font-size="8px" color="#000000">
<xsl:value-of select="mailType"/>
</fo:inline>
<fo:leader leader-length="6px"/>
<fo:inline font-family="arial" font-size="8px" color="#000000">
<xsl:value-of select="rpoStatus"/> кг
</fo:inline>
<fo:leader leader-length="6px"/>
<fo:inline font-family="arial" font-size="8px" color="#000000">
<xsl:value-of select="deliveryDate"/>
</fo:inline>
</fo:block>
</fo:block-container>
</fo:table-cell>
</fo:table-row>
</fo:table-body>
</fo:table>
<fo:table table-layout="fixed" width="556px" space-before="8px">
<fo:table-column column-width="50%"/>
<fo:table-column column-width="25%"/>
<fo:table-column column-width="22%"/>
<fo:table-body>
<fo:table-row>
<fo:table-cell padding="0px">
<fo:block font-family="arial" font-size="8px" color="#000000">
<xsl:value-of select="essence"/>
</fo:block>
</fo:table-cell>
<fo:table-cell padding="0px">
<fo:block font-family="arial" font-size="8px" color="#000000">
<xsl:value-of select="zoneDescription"/>
</fo:block>
<fo:block font-family="arial" font-size="8px" color="#7F7F7F">
Текущая зона
</fo:block>
</fo:table-cell>
<fo:table-cell padding="0px">
<fo:block-container border-bottom="0.4px solid black" height="10px" width="100%">
<fo:block> </fo:block>
</fo:block-container>
<fo:block font-family="arial" margin-top="1px" font-size="8px" color="#7F7F7F">
Новая зона
</fo:block>
</fo:table-cell>
</fo:table-row>
</fo:table-body>
</fo:table>
<fo:block-container space-before="5px" space-after="8px" border="0.4pt dashed black" width="100%">
<fo:block> </fo:block>
</fo:block-container>
</xsl:for-each>
<fo:block id="end-of-doc"/>
</fo:flow>
</fo:page-sequence>
</fo:root>
</xsl:template>
</xsl:stylesheet>
I tried to remove all indents by setting <fo:static-content flow-name="xsl-region-before" space-after="0pt" padding="0px" margin="0px"> and <fo:flow flow-name="xsl-region-body" space-before="0pt" margin-top="0pt" padding-top="0pt"> but that didn't help.
Your region-body has a margin. The flow is inside that region.